I am converting my '78 F-250 from a np435 to a C6. I believe I have all the parts laying around that I need for the conversion. I have the C6 out and in the shop and I thought I would send it out and have it rebuilt before installing it. It was a working C6 when I pulled it but that was a few years ago. My dad has a friend from high school who works at a tranny shop and said he will rebuild my C6 for $300. That includes parts and labor and boiling the case out and torque converter rebuild. My question is, is there anything special I should request to be added or upgraded? Extra clutches? Anything? I really dont know. The truck it is going in is my 78 F-250 4x4 with a built 351M (soon to be non-built 460). 4:10 gears and ARB lockers front and rear. The truck runs 40" tires off road when wheeling and 33" for city driving. The truck is 50/50 trail truck and road truck. I am also considering hanging a snow plow on it for next winter since I have all the parts for that laying around also. Any advice would be appreciateds as I really know nothing about C6 upgrades. Reason for the conversion is my dislike for clutches and shifting when wheeling and plowing and the reverse gear is shot in my np435. I have other np435's but i decided if i am going to pull it out a C6 is going in instead. Any input would be appreciated.

 

In all honestly the Ford C6 is overbuilt as it is. A Trans-Go shift kit is a pretty good shift kit, avoid the B&M.

In an all out race tranny, you could go full roller with roller bearings throughout, but very unnecessary for a strictly street build.

No matter what the transmission builder will say about modern clutches, you should still use Type F fluid.

Josh

 

Ok great advice! thanks a lot, I appreciate it! Has anyone found a quality oversized trans pan? I assume that would be recomended. I also plan on adding the largest trans cooler Napa sells and mounting it in the bed with an electric fan in addition to running it through the radiator. Just figured the bed one wouldnt get mud covered when wheeling but the radiator one would be better for highway driving.

 

Throw the biggest oil cooler on it.

I don't see the need for an oversized tranny pan. I'd just opt for a pan with a drain.

 

Here is a picture of my coolers. Two Thinline coolers, mounted in series. I DO NOT run thru the radiator with this set-up, although I may change it as it runs too cool in the cool winter months.

With the dual coolers and the Lincoln Mark VIII electric fan it is darn impossible for me to run hotter than 170, it's mostly in the 150-160 range. These last few months driving back and forth to work it woould barely get over 120 which I feel is too cold.

Josh

 

In a truck used to tow the roller bearing upgrade is a good idea as is adding an extra clutch plate and steel to the packs. A good tranny cooler, Heavy duty LOW stall converter,maybe an external filter and the E4OD planetary upgrade as well. The bearings really cut the parasitic losses that the C6 is famous for (like 30 hp I have been told)