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351 C in place of 351M

5K views 35 replies 8 participants last post by  xntrik 
#1 ·
I was wondering if anyone out there knows if there is a major difference between the 351C and the 351M I currently have a 351M in my T-Bird, but I came across a 351C that has been rebuilt and I am trying to persuade the owner to sell it since it just sits anyhow. I have an FMX tranny. Will this bolt right up? Are there any modifications I have to do? Any advice out there? I dont' want this to be a major project, just more of an easy swap.
Thanks
Chris
 
#2 ·
Hi,
The bellhousings are a different pattern on 351M vs 351C, as the 351M/400 have a taller deck height.

Not a huge deal there, though, as the FMX has a removable bellhousing anyway.

You can use a small-block ford bellhousing (289/302/351W) which IS the same as the 351C.

I'm not sure if anyone makes a stall convertor to fit FMX or not, but you'll want one of those if it's available. 351C's have big valves and ports and are real dogs until you get the RPM's up to around 2500.

You should be fine with the 351M motor mounts, I think. If not then 302/351W ones may work. I used 302 ones on my 351C in a 68 Torino. I had to move the transmission slightly (less than 1") forward, and the crossmember / frame was drilled for that.

Headers... I'd guess that the 72 Torino/Ranchero ones for a 351C would fit your (75 to 79?) Thunderchicken.

Gears ... That's a fairly big and heavy car with a short-stroke engine, so
you'll likely want lower (numerically higher ratio) say 3.50:1 or 3.73:1 with 15" tires for good street performance.

On a big boat like that, you might even want to consider a 460. It WOULD bolt up to the 351M bellhousing, and has tons of torque. The downside, of course, is that they're not known for fuel economy :p

HTH,
Don
 
#3 · (Edited)
Generally speaking =

the C is considered a small block.
the M is considered a big block.

Because that's the way stuff bolts on/ engine mounts and trans, etc. (the C and W use the same stuff)

Several good places to get stuff for FMX. Good trans, just cast iron case/heavy.
Where are you going to find a small block FMX bellhousing?
I'd just drop in a C-4 with the C and let it go at that.

If I were making the decision, I would go for a W with a C-4 (unless you can find a small block C-6/rare.)

(your $$$$$)

(a 460 will shuck that FMX quick, you'd need a C-6 in two days)

Ford Guy
 
#5 ·
xntrik said:
Generally speaking =

the C is considered a small block.
the M is considered a big block.

Because that's the way stuff bolts on/ engine mounts and trans, etc. (the C and W use the same stuff)

Several good places to get stuff for FMX. Good trans, just cast iron case/heavy.
Where are you going to find a small block FMX bellhousing?
I'd just drop in a C-4 with the C and let it go at that.

If I were making the decision, I would go for a W with a C-4 (unless you can find a small block C-6/rare.)

(your $$$$$)

(a 460 will shuck that FMX quick, you'd need a C-6 in two days)

Ford Guy
Hmmm...

My experience and opinion is that an FMX will take a way more abuse than a stock C4. I'm pretty sure that they also used the FMX behind the 390/428 FE in the 65-68 full-sized Ford and Merc, didn't they? I always thought that it was the "big transmission" until the C6 was introduced.

I had a 66 Galaxie with a 289 and "cruise-o-matic" (pretty much the same as FMX ... just a different valve body, I believe.) I replaced the 289 with a stock 1971 351C-4V. I drove the snot out of that car, and did eventually burn out the FMX at around 85,000 miles. A friend had a recently rebuilt C4, so we put that in ... and it lasted DAYS. I found another used FMX from a 66 Galaxie convertible behind a 390 and threw it in. It outlasted the differential which was the last thing to go before I sold the car.

The biggest complaint I ever had with the FMX was (as I said earlier) the convertor stall speed. It was just plain embarassing. The "legendary" Cleveland WOULD NOT move that Galaxie up an incline, (Just imagine the abuse I took from my buddies!) and I never raced from a standing start if I could help it. But at 25 or 30 MPH in low gear ... watch out!

I agree that the C6 is best suited for either a 351C or a 460 as that is what Ford usually used when they installed them. IF you can find a small-block C6, try to get the factory 2500 RPM stall convertor that were used with the Cleveland in 70-73 Mustangs.

My second "Cleveland" car was a 1968 Torino with a "built" 351C / C6 / 9-inch posi drivetrain. I took that C6's front pump out a couple of times before discovering that the dowel holes were oblonged and putting a LOT of stress on the pump. Shortly after fixing the transmission, the car was stolen ... resulting in a broken driveshaft, a hole in the floorboards, and a 3-piece (exploded internally) transmission!

If it wasn't for bad luck, I wouldn't have any luck at all! :rolleyes:

Don
 
#6 ·
351c

as stated earlyer bellhousing on the351c is different than the m. a c4 will work fine just get the right one 71 351s came with a c4 the hd one usually has the dilstick in the pan. lite duty dipstick goes into the case. 8cyl pickups and vanes have the hd trans302s and 351 winsors
 
#8 ·
ChevelleSS_LS6 said:
what's the difference between the 351Clevland and the Windsor?

The 351 as a bb ford, are you speaking of a 352 Ford Truck motor?
Ford doesn't really follow the "small block / big block" nomenclature that Chevrolet and Chrysler use.

Here is the ford engine lineup for the 60's to 90's

260, 289, 302 (5.0), and 351W (5.8W) are "Windsor" small-blocks (Was there one smaller, too? 221?) All of these engines had 6-bolt narrow valve covers, which gave them a "small-block" look. They had smaller and straight (not canted) valves, except for the "Boss 302" ... more on that below. The thermostat mounted horizontally on the front of the intake manifold, so thermostat housings were a big seller on these engines! :) Intake & Exhaust valves/ports were small in comparison.

351C, 351M, 370, 400, 429, and 460 belong to the "335 series" which all had larger ports and canted valves.

351C/M and 400 were known as the "Cleveland" engines and 370, 429, 460 were known as "Lima" engines, for thier respective assembly plants.

The "Cleveland" engines had an extended section on the front of the cylinder block that housed the thermostat and water pump. The fuel pump bolts were vertically oriented. The valve covers had 8 bolts. The thermostat housing was mounted in a vertical direction on the front of the aforementioned block extension. The exhaust ports had a staggered pattern of "one up, one down" and had individual flanges. The 351C-4V, Boss, and CJ all had huge intake and exhaust valves and ports for engines of this size. (Like a big-block Chevy or Ford "Lima" engine) 351M/400 used the same, or at least similar, heads as the 351C-2V with smaller valves and ports. 351C (2V & 4V) used the same bellhousing pattern as the Windsor engines, but the 351M/400 used the same pattern as the Lima engines.

The Lima engines were similar in appearance to the Cleveland, but not quite the same. The fuel pump bolts were horizontally oriented, similar to almost everyone else's V/8's. There was a short,straight water pump bypass hose. The exhaust ports shared a common flange, and the bolts were also in-line horizontally.I don't recall the number of valve cover bolts, but they were different than the Clevelands as well.

The "Boss 302" was a bit of a hybrid ... a 4-bolt main Windsor engine with "Cleveland" - style heads. These heads were a very close copy, but there were differences in the coolant passages.

352, 360, 390, 410, 427, and 428 are "FE series" Passenger / Light Truck engines
330, 359, 361, 389, 391 are "FE series" MD / HD Truck Engines

These babies, especially the HD ones, were big and heavy! The cast intake manifold weighs about 150 lbs. and is partially covered by the valve cover which incedentally was a 5-bolt. The water pump is mounted to the front of the block on two pedestals (similar to SB Chev). Fuel pump bolts are horizontal. Plugs are angled, with the first two facing rearward at 45° and the rear ones facing forward. The HD engines had a VERY large journal crank ... but that didn't stop them from snapping like pretzels.

HTH,
Don
 
#10 ·
KULTULZ said:
351C/351M/400 are in the "335" Series

370/429/460 are in the "385" Series



These are the "FT" Series...

The FMX was not introduced until 1968.
I stand corrected ... I do recall the "385" Series now that you mention it.

I hadn't ever heard of the "FT" designation, despite being in Ford parts for 13 years ... "shows to go you" that you can learn something new every day :thumbup: I really enjoy that aspect of posting and reading in this group.

What is your background? You seem to know an awful lot about the blue-oval stuff. :thumbup:

I still believe that the Cruise-O-Matic was the predecessor of the FMX, with minor differences in the valve body. It had the same aluminum bellhousing and a cast-iron case that attached with 4 bolts from the outside ... similar to a manual transmission.

They had "green dot" Drive which was intended for slippery conditions, basically "locking out" the kickdown, then the normal "Drive", and then "Low".

Manually shifting on these was kind of different. If you started in "L" and held it to about 60 MPH, and then "bumped" it back to "D", then quickly back to "L" it would stay in 2nd as long as you liked, then shifted back to "D" again for 3rd.

If you weren't quick enough, the trans would just skip right through 2nd and go to 3rd :p The budz used to love razzing me about being the "quick-shift" column guy. :mwink: Thanks for making me look like a dork, Henry! :D
 
#12 · (Edited)
ChevelleSS_LS6 said:
what's the difference between the 351Clevland and the Windsor?

The 351 as a bb ford, are you speaking of a 352 Ford Truck motor?
*********
351 cube C and W, (as well as M and FE) are different engines, unique to their own series. Almost nothing interchanges. I won't rehash the differences.(If I said factory built Chevy 400, would that be a big block or a small block?) Hence my earlier comments #3.

Contrary to popular belief there are minimal parts commonality between the 351 cube C and M, though they look somewhat alike, as well as engine mounts and bellhousing patterns are different. That's why they called it the M. The C bolts up like a small block, the M bolts up like a big block.
What really makes a big block or small block? Cubes or the way they bolt together?

Ok guys, bare in mind I did not say that you couldn't drill, machine, weld, grind, and hammer parts and make them fit something else.

You didn't ask but...but it is in this thread....
There are 4 different series/styles of Ford engines listed as 351/352 cubic inches, each with 4.00 bore and 3.50 stroke. (not even considering the HD series "bus" engines similar to FEs.) They are all 351.6 cubes, hence the FE engine is the 352. The W came next in 69, then the C in 70, then the M series in 73. Each designated by manufacturing plant and then M for modified (or Midland, supposedly the man behind the design?).

The (352) FE was introduced as a car engine and originally came in short 3.30 stroke 332 cubes.
The "Fairlane" small block also was originally a small bore 221 cubes (with the 289 crank stroke of 2.87).

As to whether small blocks 221>302 should be called Windsors.... (small blocks came first by 7 years).... that is controversial because that term Windsor came into common useage only after the C came out a year later in 70 to distinguish the 351s. Initially one engine series was built at the Windsor plant, the other series at the Cleveland plant. C and W.

Should a Boss 302 be called a Cleveland? The small block Boss came first and the C series used a modified design of the Boss head. The Boss 351 (C) is a different animal than the B302.

66GMC you are under a misconception as to how the green-dot works.
No time to do transmissions.... :thumbup:
 
#14 · (Edited)
66GMC said:
Hmmm...

My experience and opinion is that an FMX will take a way more abuse than a stock C4. I'm pretty sure that they also used the FMX behind the 390/428 FE in the 65-68 full-sized Ford and Merc, didn't they? I always thought that it was the "big transmission" until the C6 was introduced.

A friend had a recently rebuilt C4, so we put that in ... and it lasted DAYS.

The biggest complaint I ever had with the FMX was (as I said earlier) the convertor stall speed. It was just plain embarassing. ......

Shortly after fixing the transmission, the car was stolen ... resulting in a broken driveshaft, a hole in the floorboards, and a 3-piece (exploded internally) transmission!

If it wasn't for bad luck, I wouldn't have any luck at all! :rolleyes:

Don
**************
Did I say STOCK C-4? Where would you get a NOS C-4 anyway?
So you found one bad used C-4. ok, so what? You had a bad used C-6 too.

C-6 came out in 1966 models.

The FMX/cruise-o-matic evolved from the 50s Ford-o-matic and was used until 1980.
Never saw a 428 with an FMX.

Before 66 muscle cars used the Lincoln big transmission, a cast iron cruise-o-matic. Used in FE and MEL Lincolns and T-Birds, etc. (Check out Tasca's first 62, 63, 64 Thunderbolt cars-- ya 62)

Small block C-6 came in early 70s 351W vans mostly.

C-6s were used mostly behind big block and heavy vehicles.... 351W, 351C, 390, 410, 428, 400, 429, 460.

70s cars: 351W had C-4s, 351Ms mostly FMXs, 351 Cs FMX, 400s had C-6s.

Geez no wonder you went to Chevys, with all that bad Ford stuff...lol
 
#15 ·
small block fords

66GMC said:
Ford doesn't really follow the "small block / big block" nomenclature that Chevrolet and Chrysler use.

Here is the ford engine lineup for the 60's to 90's

260, 289, 302 (5.0), and 351W (5.8W) are "Windsor" small-blocks (Was there one smaller, too? 221?) All of these engines had 6-bolt narrow valve covers, which gave them a "small-block" look. They had smaller and straight (not canted) valves, except for the "Boss 302" ... more on that below. The thermostat mounted horizontally on the front of the intake manifold, so thermostat housings were a big seller on these engines! :) Intake & Exhaust valves/ports were small in comparison.

351C, 351M, 370, 400, 429, and 460 belong to the "335 series" which all had larger ports and canted valves.

351C/M and 400 were known as the "Cleveland" engines and 370, 429, 460 were known as "Lima" engines, for thier respective assembly plants.

The "Cleveland" engines had an extended section on the front of the cylinder block that housed the thermostat and water pump. The fuel pump bolts were vertically oriented. The valve covers had 8 bolts. The thermostat housing was mounted in a vertical direction on the front of the aforementioned block extension. The exhaust ports had a staggered pattern of "one up, one down" and had individual flanges. The 351C-4V, Boss, and CJ all had huge intake and exhaust valves and ports for engines of this size. (Like a big-block Chevy or Ford "Lima" engine) 351M/400 used the same, or at least similar, heads as the 351C-2V with smaller valves and ports. 351C (2V & 4V) used the same bellhousing pattern as the Windsor engines, but the 351M/400 used the same pattern as the Lima engines.

The Lima engines were similar in appearance to the Cleveland, but not quite the same. The fuel pump bolts were horizontally oriented, similar to almost everyone else's V/8's. There was a short,straight water pump bypass hose. The exhaust ports shared a common flange, and the bolts were also in-line horizontally.I don't recall the number of valve cover bolts, but they were different than the Clevelands as well.

The "Boss 302" was a bit of a hybrid ... a 4-bolt main Windsor engine with "Cleveland" - style heads. These heads were a very close copy, but there were differences in the coolant passages.

352, 360, 390, 410, 427, and 428 are "FE series" Passenger / Light Truck engines
330, 359, 361, 389, 391 are "FE series" MD / HD Truck Engines

These babies, especially the HD ones, were big and heavy! The cast intake manifold weighs about 150 lbs. and is partially covered by the valve cover which incedentally was a 5-bolt. The water pump is mounted to the front of the block on two pedestals (similar to SB Chev). Fuel pump bolts are horizontal. Plugs are angled, with the first two facing rearward at 45° and the rear ones facing forward. The HD engines had a VERY large journal crank ... but that didn't stop them from snapping like pretzels.

HTH,
Don
THERe WAS A 221 SMALL BLOCK same cubes as the 1st flathead.351m and 400 m used the 2v 351c heads
 
#16 ·
66GMC said:
I stand corrected ... I do recall the "385" Series now that you mention it.

I hadn't ever heard of the "FT" designation, despite being in Ford parts for 13 years ... "shows to go you" that you can learn something new every day :thumbup: I really enjoy that aspect of posting and reading in this group.
The FT Series is actually nothing more than a beefed FE. They (330-361-391) were introduced in the 1964 model run to replace the FORD Y-BLOCK 272HD and the LINCOLN Y-BLOCK derivatives 302 and 332ci. The FT Series was later replaced by the 370/429 for medium gasoline truck. You wouldn't be familiar with them unless the dealer you worked at was also a FORD HEAVY TRUCK DEALER (now gone).

What is your background? You seem to know an awful lot about the blue-oval stuff.
I am an old fart and worked in my first FORD dealer in 1967.

I still believe that the Cruise-O-Matic was the predecessor of the FMX, with minor differences in the valve body. It had the same aluminum bellhousing and a cast-iron case that attached with 4 bolts from the outside ... similar to a manual transmission.
The COM was a design progression of the older FORD-O-MATIC. It was introduced in 1958. Later upgraded in 1961. It featured a DUAL RANGE gear selection. It would start in either first or second depending on how the gearshift lever was positioned. The FOM was actually a three speed but with second gear start. If you wanted LOW, you had to position the gear selector in LOW from takeoff or fully open the throttle. The FMX (FORD-MERCURY-DUAL RANGE) was the final design culmination of all designs preceding it.



Am Looking For Factory/Aftermarket Speed Parts For The MEL (Merc-Edsel-Linc-TBird) Engine Family (383-410-430-462) Produced From 1958 To 1968

Also Early FORD Special Service Tools
 
#17 ·
xntrik said:
*********
:confused: Is it snowing up your way already?

351 cube C and W, (as well as M and FE) are different engines, unique to their own series. Almost nothing interchanges. I won't rehash the differences.

Contrary to popular belief there are minimal parts commonality between the 351 cube C and M, though they look somewhat alike, as well as engine mounts and bellhousing patterns are different. That's why they called it the M. The C bolts up like a small block, the M bolts up like a big block.
I believe there is a lot more commonality than you give it credit for.

As to whether small blocks 221>302 should be called Windsors.... (small blocks came first by 7 years).... that is controversial because that term Windsor came into common useage only after the C came out a year later in 70 to distinguish the 351s. Initially one engine series was built at the Windsor plant, the other series at the Cleveland plant. C and W.
The 221/260/289/302/255/351W are all members of the FORD Ninety-Degree Family. We all know why FORD had to designate W, C and M.

Should a Boss 302 be called a Cleveland?
No.

The small block Boss came first and the C series used a modified design of the Boss head. The Boss 351 (C) is a different animal than the B302.
The CLEVELAND had already been designed and tested when FORD engineering got the idea of adapting the head designs to the 302. It was to replace the 302 Tunnel Port heads used in 1968. The BOSS 351 engine was nothing more than a highly modified 351C 4V engine. It was released (as a package) due to racing sanctioning bodies allowing late increasing cubic inches in TRANS-AM. The BOSS 302 cylinder head (and intake) are dedicated pieces released only for the smaller 302. To actually put them on a CLV block would require a host of modification(s).
 
#19 ·
KULTULZ said:
:confused:

I believe there is a lot more commonality than you give it credit for.

The 221/260/289/302/255/351W are all members of the FORD Ninety-Degree Family. We all know why FORD had to designate W, C and M.
*************
C and M = What common parts besides heads and cam? Not sure about distributor. M uses a 460 distributor.

I have never heard the term "FORD Ninety-Degree Family". Please explain.

Actually I find a lot of people who don't know about the W, C, M designations.

Smile :) when you say "Old Fart". ;)
There may be snow on the roof, but there's still fire in the furnace.
thanks,
x
 
#21 ·
KULTULZ said:
I believe there is a lot more commonality than you give it credit for.

The 221/260/289/302/255/351W are all members of the FORD Ninety-Degree Family. We all know why FORD had to designate W, C and M.
xntrik said:
*************
C and M = What common parts besides heads and cam? Not sure about distributor. M uses a 460 distributor.
Well, there you go. The C uses the 385 Series distributor also.

I have never heard the term "FORD Ninety-Degree Family". Please explain.
The cylinders form an upright ninety-degree angle. I ass-u-me this is why FOMOCO identified the engine family as such.

Actually I find a lot of people who don't know about the W, C, M designations.
Then they are not TRUE FORD BLUE... :D

Smile :) when you say "Old Fart". ;)
There may be snow on the roof, but there's still fire in the furnace.
The only fire this Old Fart has in his furnace is heartburn... :(
 
#22 ·
About the "green dot" Ford transmissions:

One position locked the trans in 1.
One position auto shifted 1-2-3
One position started out in 2 and auto shifted to 3. for slippery weather starts.

The 1-2-1 shift did lock the trans into second, if you caught it before the governor shifted it. (depending on how far you over revved it.) Slowing down while in second, it would auto downshift to 1. If I remember correctly my 58 FE car did this also. The AOD trans having only 1, D, O on the shifter does this 1-D-1 lock into 2 gear also.

The C-4 had variations in valve bodies, but stuck to 2 basic shifter patterns. As described above and the other being the later models with
one position locked in 1.
one position 1-2 auto upshift
one position 1-2-3 auto shift

One rare valve body variation was an auto 1-2-3 upshift at @ 4800. If "locked" in 1, it would auto shift to 2 at 5800, like it or not.

Duke might have more precise info. I never "did" transmissions.

x
 
#23 ·
xntrik said:
About the "green dot" Ford transmissions:

One position locked the trans in 1.
One position auto shifted 1-2-3
One position started out in 2 and auto shifted to 3. for slippery weather starts.

The 1-2-1 shift did lock the trans into second, if you caught it before the governor shifted it. (depending on how far you over revved it.) Slowing down while in second, it would auto downshift to 1. If I remember correctly my 58 FE car did this also. The AOD trans having only 1, D, O on the shifter does this 1-D-1 lock into 2 gear also.

The C-4 had variations in valve bodies, but stuck to 2 basic shifter patterns. As described above and the other being the later models with
one position locked in 1.
one position 1-2 auto upshift
one position 1-2-3 auto shift

One rare valve body variation was an auto 1-2-3 upshift at @ 4800. If "locked" in 1, it would auto shift to 2 at 5800, like it or not.

Duke might have more precise info. I never "did" transmissions.

x
Yup, OK, I'm sure you're right on this ... it's been a lot of years, and I was still just a stupid 17/18 year-old when I drove that car. I'm still reasonably sure that I remember that it would not downshift from 3-2 in the green dot position either.

I used to love that "auto downshift" (2-1) thing too ... that's how I used to get the "hot wheels" guys to race me. :mwink:

I'd pull up alongside them going down the cruise circuit at around 25 or 30 MPH in 2nd gear ... stab the throttle to trigger the downshift (usually accompanied by a tire chirp for attention) and voila 3,000 RPM ... right in the Cleveland's power band :thumbup: :evil: That (1971) Cleveland-powered 66 Galaxie gave quite a few of them a bit of a surprise. Heh-heh-heh
 
#24 ·
KULTULZ said:
Why forget it? How else is information to be exchanged if you do not participate?

I too do not enjoy arguing. Leave that to the seventeen year old BOW-TIE BOYS... :thumbup:
I was in a bad mood yesterday ... and getting a little testy.

Then I recalled my mom's advice:
"Keep your words tender and sweet ... you never know when you'll need to eat them ..." and removed my own post.

I agree that this has been a very informative thread, in fact ... perhaps all of this could be summarized and kept as a "sticky".

You say "old fart" ... but there's nothing like "being there when it happened", and being a valuable resource of information for those that weren't.

I sort of "followed my uncle's footsteps" too. He worked in Ford parts from about the time I was born (1957) until just a few years ago, when he retired.

I currently have an opportunity to "go back" to Ford ... I'm meeting with the dealer principal at lunch today to discuss it. I'm feeling like I could use a change after working in the same NAPA store (2 different owners) for the last 13 years. As I'm sure you know, it seems the only way to get a raise in this business is to make a move.
 
#26 ·
I should compile the info and request that Jon make a sticky of it, or post it in the FAQs. I'll be sure to post it for your approval, I don't know a whole lot about the Blue Oval, but I sure would drive one over foregin most-anything any day of the week! :thumbup:
 
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