[7StangG2]

Im looking to see if this swap will work or not. I have a 72 mustang grande, 351w with a c4. I have a c6 trans that is with a straight six engine in a truck. I need to replace the trans in the mustang. Question is will the c6 from the truck bolt to the windsor? The bellhousing pattern for the windsor from what I know is the same as the 240-300 straight six engines. Will this c6 bolt to the windsor and be made to work or not? Thanks in advance..

[woodz428]

All SBF engines use the same bellhousing pattern, not an issue. However, not knowing the truck vintage there may be some mount changes needed, although they can be done with stock parts. Are you sure it is a 351W AND a C4?? All the 351Ws I had in early stangs were FMX trans.I think the sixes and 302s were the only C4 equipped cars by then.........I'll know for sure in a few minutes, since I am in the house and the books are in the shop.

[galaxieguy3]

Easy way to tell if it is the FMX trans, besides pan shape, is to look at the main center section of the trans. The FMX has a steel case with aluminum bell and tail. C4 to my knowledge is all aluminum. I have swapped a C6 into a FMX application, everything fit no problems at all. The tail end was just a whisker longer on the C6, but not too long that I couldnt use the original driveshaft. I am not sure on the length of the C4 compared to a C6 though. That is easy enough to determine with a measuring tape. You may end up having to pull the pan and change the shift lever up or down. I think floor shift versus column shift determines which direction it goes. Not a big deal. I assume the driveshaft yoke would interchange, but wouldnt swear to it. Not sure if any of this helps you, but good luck.

[galaxieguy3]

Oh by the way, you may need a 351W-C6 flexplate. The flexplates were different between my FMX and C6. There again not sure about C4 to C6. FYI

[7StangG2]

Originally Posted by woodz428

All SBF engines use the same bellhousing pattern, not an issue. However, not knowing the truck vintage there may be some mount changes needed, although they can be done with stock parts. Are you sure it is a 351W AND a C4?? All the 351Ws I had in early stangs were FMX trans.I think the sixes and 302s were the only C4 equipped cars by then.........I'll know for sure in a few minutes, since I am in the house and the books are in the shop.

Yes, it is a 351w and a c4, the 351 though is not the original motor as far as I know, I was told the original was a 302. Then again the guy I got it from thought the engine was a 351c, so im not sure if he is right on it having an original 302.

What about the input shaft from going c4 to c6??


Galaxieguy, all information helps, glad to know it shouldnt be much of a probelm going from column to floor shift that would be one of more questions after I find out for sure it would bolt to the windsor and fit. The c6 trans is in the truck and running and all so I have everything there, if I would have to use anything else maybe..

Im ready to do the swap so I can get this mustang on the road asap I didnt think I would have to do the trans but.. I posted on another forum and was simply told it wont work by a few.. I assume this swap will work???

Thanks

[eloc431962]

yes the swap will work c4 to c6 done it but it has been awhile. like galaxieguy said you probably will have to change the flywheel and i am not sure about the drive shaft either. when you get the trans in you can measure to find out hope this helps. cole

[onebadmerc]

The transmission crossover is different on a C6,FMX equipped 71-73 Mustang. The C4 transmission crossover will not work, you will need one off a C6 or FMX equipped 71-73 Mustang or Cougar. Here is a picture of one on Ebay.
http://cgi.ebay.com/ebaymotors/1971-...2em118Q2el1247

[eloc431962]

onebadmerc is right about the crossmember it is different. and dont forget about the shift lever if you are still using the mustang floor shifter.if the c6 is not sit up for the floor you will have to change the shift lever or buy an aftermarket universal floor shifter then it will work.good luck hope everything works out.

[7StangG2]

what about the input shaft splines going c4 to c6 or how does that work really?? Im about ready to go forward with it, thanks for the help everyone..

[cliff tate]

you best be sure that the flex plate you use is correct, 351w is different weight than latter 302sand 5ltrs, other wise you will have a vibration. cliff

[7StangG2]

Will this flex plate work for 351w with c6's, link here


http://www.jegs.com/i/B%26amp%3BM/130/40232/10002/-1#

Or will I just need to double check how many teeth?

Thanks!

[Irelands child]

Why not just rebuild the C4 and save a bunch of time, expense and fit up headaches? The C4 is easily upgraded and more reasonably then the C6 plus is good for at least 450Hp with minimal outlay.

Here are a couple of interesting Ford trans links:

http://www.fordmuscle.com/forums/c4-...-version2.html

http://raceabilene.com/kelly/hotrod/trans.html

Dave W

[7StangG2]

It may be more harder but im sure cheaper than rebuilding the c4 professionally. I have the c6 already and I know its good, never had a problem with it in the truck. Plus I dont know what I will be doing to the engine, but it will be built more sometime.

[Irelands child]

You can do it yourself for ~$240. They are simple - no electronics, no OD - just a few clutches and plates and a bunch of gaskets.

http://store.summitracing.com/partde...5&autoview=sku

Here's one "kit" - and with the Ford manual which I can forward via email(not PM) or you can pull from any early Ford Shop Manual plus the info on the other attachments, no real problems doing a C4......but of course, it's your choice.......

Dave W

[woodz428]

That trans mount looks the same as the FMX and C6 trans....I think the manual ones too. I have 6 in the shop, the C4 is different. I would verify that it is a 351W, it's easy to tell since the lower intake manifold surface is even with the dist opening on the 302 and about an inch and a quarter above on the 351W. A casting number on the intake will help if you are unsure about the dist reference.If he thought it was a Cleveland and couldn't tell..it may still be a 302. Input splining is irrelevant since you have to use the torque converter that's with the trans. I think that the FMX and C6 use the same bolt pattern on the convertors and will need to check the C4, that's in relation to the same engine, since there are several flexplates depending on the engine.
If you post the engine code from the serial number( I think it's the 5th didgit and it will be a letter surrounded by numbers) it is easy to tell you what was in it originally too.
If you decide to do the swap, PM me and I can tell you all the parts that interchange as well as what you need to replace and from what vehicles. I'll have to look at my manuals after lunch, but that trans mount looks like all the '67 upward for the trans I listed.