C4 to FMX

Reply Subscribe

Thread Tools

Search this Thread

Jun 10, 2010 | 04:36 PM

79FordBlake

Thread Starter

Posting Guru

Joined: Feb 2007

Posts: 1,735

Likes: 2

From: Wingo, Ky

C4 to FMX

I have asked this question before but I never got a response that made me feel 100% sure about the subject. Will a FMX transmission bolt right into the place of a C4?

The reason I am wanting to know is the C4 I have now is goin out and I have a good FMX.

The FMX is in a 74 F100 longwheel base, 302.

If it is a direct bolt in it will be goin in my 73 F100 shortwheel base, 302.

I know for sure the trans lines are different and I will have to swap those out. I didn't know though if maybe the flywheels might be different or the torque converters.

The 74 longwheel base has a two peice driveshaft with carrier bearing. I have a 79 longwheel base F150 and its a one peice. Whats the reason behind this?

Thanks.

Jun 10, 2010 | 05:13 PM

jim collins

Cargo Master

Joined: Apr 2009

Posts: 3,038

Likes: 4

From: South west Idaho

My 79 f-150 had a two piece driveshaft and the 79 f-100 I have now has the one piece drive shaft. I believe the reason for a two piece is balance. A long drive line is harder to balance and some times it has to do with keeping the rear end angle correct. I can't help on the tranny change. If everything bolts and the fmx turns out to be longer than the c/4 you can move your motor mount perches ahead. There's lots of room with a 302. I just moved mine ahead today to get a 460 with a c/6 to fit the way I wanted it to. The crossmember for the transmission in a 79 can be moved along the frame ,mine had three different predrilled places for it to bolt to.I don't know if a 73 is that way or not .Good luck. JIM