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Discussion Starter #1
I have access to a free rebuilt c6 tranny. I would rather use this behind a 351 c than a brocken down c4. My question is- WIll it just bolt right in place of the c4? Does it use the same crossmember? Will I have to get a different driveshaft? What about ujoints and yoke? Will they work on a c6? If anybody has ever done this conversion I Would like to email you. Im wondering if this is a possible conversion for somebody who knows zero about trans/driveshaft. Thanks for the help.
 

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There are two different types of C6 trannies, small block and big block. You need the small block C6. Find this out first.

Sorry I can't be of more technical help.
 

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everything is different

small block pattern c6 w/converter
small block/c6 block plate
small block/c6 flywheel
c6 crossmember
c6 driveshaft for your year stang
c6 dipstick

the starter for the c4 will work with the c6, as will the tranny rubber mount

also bear in mind some headers that clear the c4 WILL NOT clear the c6...I had standard heddman hedders for a 2V cleveland in a 69/70 that weren't supposed to clear a c6 that JUST BARELY did (if I turned the collectors so a flat side was closest to the pan of the c6 I had 1/2" of clearance.....kinda pushing it!!)
 

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Don't let the daunting *G* task of adapting the C6 to your car get you down...just take it one step at a time; you might find it's simpler than you might think at first.

Bottom line is to verify that the C6 is for a small block...I have such a core in the shop and can give you the dimensions across the top of the bellhousing along with a picture of the case to help you ID it. A free rebuilt small case C6 is nothing to sneeze at, especially if you've got a warmed-over 335 series to stick it behind. I'm assuming you have a later Pony (67-up) which has the tunnel room for a C6...

I've had good luck with a C4 behind the 351W in the race car, but it's light and has a lot of gear, lessening the loads on the trans.

Get back to us if you require more assistance...
 

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Get me some closeups of that tunnel....no way a C6 would fit in the race car...I tried.....the stiffeners hit and the case radius near the pan flange did as well. I guess I could've lowered the engine in the car but I was dealing with ground clearance problems anyway due to retaining the wet sump oil pan and using and undercar (as opposed to fenderwell exit) header system.
Even with the C4, with the engine 1 1/2 inches back, I had to bang a clearance into the firewall for access to the bellhousing bolts....and the scattershield is right up against the tunnel.

That was part of the reason I decided to go to a Powerglide if I built a Super Gas 385 series combo...a C6 wouldn't fit without major surgery (I did n't want to completely front half the car, going to a Pro Stock chassis)...as you can see, mine is a hybrid of PS technology and OEM Ford.

If you or the builders of your car did make the C6 fit without modification, it is something I'd be very interested in learning about...

Or, did you mean " who cares if it doesn't fit the tunnel" ?? *G*
 
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Discussion Starter #7
Actually there are 3, Windsor/Cleveland, FE, & 385. My question in why even dump the C-4. I have run them behind 429 SCJ's in the 11's with a stock, fresh trans & my Super Comp Mustang has one too. She never fails(like the 30 odd C-6's) & with the bottle I put over 1000 HP(from the dyno!!!) to it. I can probably re-build a C-4 faster than you can find the parts to swap it. Get the trans, by all means, but think before you act, it might help you out later. BTW here'a a pic of my POS race car.
http://www.tulsahotrods.com/CarPics/dragmustang/drag03.jpg
 

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I had a C6 in my '66 fastback.As I recall,we had to cut a square piece from the driver's side of the bellhousing that protruded about one inch.We cut it off with a jigsaw,no problem.It was a tight fit,but I don't remember hammering anything.The crossmember was the most work,it was fabricated from one inch round bar stock and 3/16 plate.Also,the emergency brake lever had to be adapted to the crossmember.The C6 is heavier than a C4,and has more internal friction(the C4 has less than most automatics).The friction issue can be avoided with a roller bearing kit to replace the thrust washers available from ford or many of the aftermarket suppliers.My car ran almost two tenths slower with the C6 as compared to the fmx it replaced.I don't how it will compare to the C4,but I'd bet the results would be similar.I would go with the C4,even if the C6 is free.It just doesn't seem worth the trouble and the C4 is adequate for any street application.Hope this helps...
 
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