C4 Trans in 37 Ford Coupe

F

Ford1933

Senior Member
I am thinking of installing a 78 Ford C4 trans in my wife's 37 Ford coupe with stock engine that has just been rebuilt. I plan to retain the original rear end which I assume is a 4:11 gear. Does this engine have enough vacuum capability to shift this transmission. I would be using the Flat-o-Matic adapter .

Thanks
Mick
 
You need to make sure flat-o-matic MAKES an adaptor to mate the C4 to your 37 engine first. I know they have them for later flatheads but don't know about the 37. Also, if you go to an automatic, you'll have to change the rear to an open drive and you will likely be more happy with the result if you replace the rear suspension with a Chassis Engineering parallel spring kit and late model Ford rear end which will give you a higher ratio as well. Good luck. Al
 
It's not to bad to put one in a 49 or later car but they have less crossmember right around that area. I've heard of them put into a 1940 car with some mods to make it fit the space. It seems like I read that on the HAMB forum at the Jalopy Journal site.
 
I have a C4 in my 32 high boy behind a 49 merc.It works great ,no problems with vacuume.They make it to fit 32-53 so that is no problem.You will have to fab the cross member to mount the rear of the trans and as stated will most likly have to run a open drive shaft.
 
I don't see why it wouldn't work with the Banjo rear end, but as already stated, you'll need an open drive conversion kit and a new driveshaft. Your rpms will still be pretty high though.

I have a C4 in my '36 but I have a Granada rear end. (technically it is a C5... found THAT out the hard way!)

I'm not positive anymore but I think I have the Chassis Engineering crossmember kit. It's a real pain to bolt in unless you drill holes in the plate to access the bolts. Of course it is 20 years old too, so they may be different now.
 
You have to be mindful of horse power when you use a c4 the servo pistons are problematic over 350 hp or if you use a stall, you also may end up having to use a vacuum can to get some reserve vac capacity for smooth shifts. If you have the clearance I would use a c6.
 
I have a c4 with and 8ba in my 39 ,not on road just ,used up street dirt road and shifts good.Flatomatic is the only way to go with that motor.I used the Speedway kit,that uses a 12 volt 302 starter.
I also used the Chassic Rear end kit with Granada rear.Still working and waiting to test ride on the road.What a difference no more grinding gears and noise. Way to go.
 
I have a friend with a c4 in a 40 and Chassis Eng. mounting plates; all works well. One minor issue with mechanical speedo cable; it would have required extra hole in X on drivers side for access. My friend went with electric speedo.
 
Ford1933 said:
I am thinking of installing a 78 Ford C4 trans in my wife's 37 Ford coupe with stock engine that has just been rebuilt. I plan to retain the original rear end which I assume is a 4:11 gear. Does this engine have enough vacuum capability to shift this transmission. I would be using the Flat-o-Matic adapter .

Thanks
Mick
Click to expand...
I have a C4 with a Gearvendors OD behind a 351W and a Versailles rearend,CE modification kit for the crossmember,and a CE rear suspension kit in my 40.You'll have to cut or drill out the rivets holding the center section of the X member,the CE modification kit just bolts into the old holes.It fits beautifully.you don't have the butcher the xmember.
The problem with installing a C4 behind a 48 or older flatty is the bell housing extension on the block,you'd have to install the Torque converter onto the flexplate,and then stab the trans.
 
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