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Big Block/Small Block - Ford

6K views 12 replies 8 participants last post by  KULTULZ 
#1 ·
Ok, I'm getting confused here. Someone just told me a 351C is a small block, but the 351M/400 is a big block. They're all in the same family though, right?

Now I know about the 351M/400 sharing the same tranny bolt pattern as the 429/460, cause of my Bronco and the 429 swap I'm doing.

I was always told that the 352/360/390FE and the 385 series (429/460) were the Ford big blocks. Now I learn that the big block/small block differention is only in the tranny case bolt pattern? :confused:

So, is there no difference (the block itself) in big block/small block...other than the obvious difference in cubic inches and the tranny bolt pattern?

[ November 03, 2002: Message edited by: BigBlockBabe ]</p>
 
#2 ·
I wish I knew for sure, I would love something in print because of the amount of different answers on this issue. I wonder if Ford even knows! Our two residents that might know are 4-jaw and KULTULZ. Haven't seen KULTULZ for a bit though but 4-jaw is usually floating around.
 
#3 ·
Technically the 351M/400 is a small block (335 series like the 351 Cleveland)it shares the same bore spacing, cam to crank centerlines etc. It is however massive by comparison and some do refer to it as a big block, probably because it shares the bellhousing pattern and motor mount bolt pattern with the 385 series (429/460). The 1973 400s installed in big Fords however had a regular smallblock pattern. Since dimensional parameters are what puts an engine in whatever class the 351M/400 is really a large smallblock.

[ November 03, 2002: Message edited by: woodz428 ]</p>
 
#4 ·
Ok... Ill take a stab at this.
Ford has had a half a bilion different engine families... Ill touch on each thats been used in a perf. application...

FE ?-1970 or so... 352 to 428, including the infamous 427... Big block, canted valves... very good motor. HEAVY!!

385 series Big blocks- 429/460 Giant torque monsters! Great motor...

302/351w Small block, straight valves, nice, but small, although ive heard of 427 stroker 351s

351/400 C and M- These are a big debate... not a very desirable motor... nice heads for a 302 there though... these have the same bore spacing, etc small block, tranny patterns of a 385.. canted valves... weak bottom ends... I call em a small block, but FRPP calls em big blocks... hard to say... 351C-4v heads are essentially the Boss 302 heads... I believe the manifold pattern is different... special manifolds are available from bush performance to put 351c/m heads on a 302...
 
#6 ·
Lets clear up a few misconceptions...

335 Series engines are small blocks,
385 Series engines are big blocks,
FEs are neither, they're FEs
Y-Blocks are neither, they're Ys
Windsors are small blocks,

There are FEs that are smaller CI wise than
335s and 351Ws, and 335s that are bigger than
one 385(400 vs 370).

The last thing, The 335 is not a weak block,
big power is to be had when the proper combo
of parts is thrown at it.

Oh yeah, the 351M/400 head is not a 351C 2bbl
head, the exhaust port cannot be smoothed out
like a C head, you'll hit water...and the early Boss 302 head is a different animal altogether,
it has 351C ports/valves while the later had
smaller ports/valves...

Steve & the Rockette...
Too many to list...
 
#8 ·
"FE ?-1970 or so... 352 to 428, including the infamous 427... Big block, canted valves... very good motor. HEAVY!!"

No FE had canted valves, they are in line, except the rare SOHC hemis.


"I was always told that the 302 Boss was a 302 with 351C-2V heads not 4V heads but I don't have anything in print."

The Boss 302 (in 69) had the pre cursor to the 351C 4bbl heads with slightly larger, .060, valves. The 70 head had the same exact size valves, the water passages on the heads and the valve keepers, single groove as opposed to multi groove were different( although the later Boss 351 used single groove), though can be swapped either way with some minor modification.

[ November 05, 2002: Message edited by: woodz428 ]</p>
 
#10 ·
Originally posted by Canzus:
<strong>
Steve & the Rockette...
Too many to list...</strong><hr></blockquote>

Dude! That sounds familiar. Steve and the Rockette...were you on the FTE email list??

That's a good lookin' '57 in your avatar by the way. :D

Thanks for all the info guys. Cleared up some stuff and I'm writing this down in my little book of Ford stuff. :cool:
 
#11 ·
Big block vs small block, the great debate.

The factory decided at their little marketing meetings what they should call an engine, it has no basis in reality. I used to say that any engine that had a big block bolt pattern for the trans was a big block but even that can be shot full of holes if you consider the 351C which could have either pattern.

Basically you could say the terms were basterdized by the manufacturers and their marketing men long ago and nowadays are totally useless terms unless you want to argue forever about it.

Think of it this way, do you think a 400 Chevy small block is any better than a 400 Pontiac big block assuming all else is equal?

I didn't think so, the terms are useless unless you want to impress someone.
 
#12 ·
Originally posted by 4 Jaw Chuck:
<strong>Big block vs small block, the great debate.

I didn't think so, the terms are useless unless you want to impress someone.</strong><hr></blockquote>

Well, YEAH! Why else would a GIRL go to all the trouble of learning this USELESS engine stuff. lol!

Nah, seriously though. I'm constantly hungry for more engine stuff, especially Ford specific and this was just something that I was curious about. I've learned a great deal from this thread though. :D
 
#13 ·
In the olden golden days of FoMoCo... :)

The 90 degree family (221 thru 302) was referred to as a Small Block. The FE series {332-428) was referred to as Big Block.

The 385 Series came along and then began being referred to as Big Block, delegating the forgotten 390's to FE status.

The 335 Series is regarded as Small Block.

I guess you could even say that the Y-Block was the Small Block of it's day as it was over shadowed by the LINCOLN Y-Series (347/368).
 
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