Topic: c4 to c6 swap

[mustangwannabe302]

i am currently using a c4 tranny on its last leg and until i can get it rebuilt im using a c6.  my 302 came out of a 78 lincoln versaille and the c6 came out of a 84 ford f150 what kind of difficulty am i looking at here? i know about cutting the driveshaft and different crossmember other than that do i need to change my flex plate? will my harmonic balancer create a problem?

[Soaring]

The driveshaft output shaft on the C4 is smaller than the C6 shaft, thus the old one piece driveshaft cannot be used.  You'll have to get a new driveshaft made up.  You'll have to have a two piece shaft made. Either way it's probably cheaper to go to the junk yard and get the ends and have the tube made up, or just take a C6 shaft with the ends left in tact and have the machine shop shorten it and balance it if needed.  When I had my drive driveshaft on my Kit car custom made, it cost me about $125, but some machine shops will try to stick it to you, so shop around.   Be sure to take very careful measurements as to the length. 

[mustangwannabe302]

what kind of c6 flexplate will fit safely on the 302 because i know there are alot of variables like the harmonic balancer, teeth count and the actual diameter of the flexplate. is there some kind of special conversion flexplate i can get or can i use one off of anohter vehicle?

[rmodel65]

why not go with an AOD instead of the C6? since your gonna need to mods parts etc

[Soaring]

You have to know the year of that 302.  Up until 82 the imbalance was 28 oz, and from 82 on it was 50 oz.  The C6 flexplate is larger than the C4, so you have to get a flexplate for a C6 for the correct year model of engine.   It has 164 teeth.  It will come with a counter weight because it is balanced externally, so you have to know what year to get.   Use blue loctite and torque to 125 lbs. 

[jethat]

I to would go AOD not worth the hassle to change over to the c6. Keep the low horsepower drag C4 or go with the AOD. The AOD is the same design as the C6 with the taller over drive gear. The C4 uses the least horsepower of any Ford tranny and is second only to the power glide.