Hot Rods 63 Comet C4 Conversion

Hey HAMB,
Project is coming along. Rebuilding up a 66 289 for my 63 Comet. Need to ditch the old Merc-o-matic 2-speed. Picked up a C4, but the tranny mounting is way different. Current crossmember is about 3 inches further back than the mounting bolts for the C4, not to mention the C4 mounting pattern is totally different. Anyone out there got any ideas about fitting out the Comet for a C4?
Thanks as always,
RNY

 

https://www.ebay.com/itm/1961-65-Fo...619767&hash=item2aeafb2257:g:uRMAAOSw7OdcURAZ

I’ve got this on my 65 Falcon...bolted right up to what was a 6 cylinder Futura model...now a 289 / C4 combo

 

Yep, one of those. Do shop, I've seen them cheaper and more expensive. Unless you have a '64-65 Falcon/Comet C4 tailshaft housing that has the weird mount....

 

And yes..look around.. I payed way less than that..I wanna say 80 bucks or so..on EBay..

 

https://www.ebay.com/itm/1962-1963-...230253?hash=item287deac72d:g:0ocAAOSwevJeC6hr

I think this is the same..this is the one I bought for my Falcon..painted it myself..saves some $$$$..it’s a nice piece!

 

FalconParts.com …. $79.95

LynnW

 

Hey @loveoftiki - that looks like it'll work! Thanks man.

 

Also, I realize that the since the C4 is about 2.5 inches shorter than the merc-o-matic, my drive shaft will end up being too short. Is there a longer yoke out there?

 

Nope, not that much longer. You'll need a longer driveshaft.

 

Actually I measured the overall tranny length and the C4 is only about an inch shorter. I should be able to use the same drive shaft I think.

 

Be careful with that... The rule of thumb is you push the yoke all the way into the trans then pull it out about 1" to 1.5". Go beyond that and there's a very real risk of not having enough spline engagement as well as allowing excess radial play. I don't know what the minimum spline engagement should be, but I wouldn't go under 50% and I'd make very sure that the yoke isn't worn and the tailshaft bushing is good also. Even a small amount of radial play can quickly take the bushing out, then the output shaft.

In the '60s and newer there wasn't that many U-joint sizes used, Ford and GM used some of the same sizes on various models, you may be able to find a correct-length driveshaft at a boneyard.

 

I’ve seen extra long yokes listed somewhere, they are about 2” longer than stock. Can’t remember right now where I saw them....

 

You have to be careful with those, on most I've seen that are longer the extra length is 'blank' inside, no additional spline length.

 

You could be right, I've never seen one in person, only in a catalog or a web site.