Help with shift kit for c-6

[56 Ford]

My son and I recently rebuilt his 79 f-150 4wd
472 ci
lunati cam 213/219 @ .050 535/540 lift
weiand stealth
PI heads
short headers
3'' exhaust with crossover
holley 670 street avenger
4.56 gears
12.5 - 35 tires


It has a stock C-6 tranny that shifts kinda mushy
we want to put a shift kit in it but don't know what brand is good for his application. he runs it mainly on the street but sometimes in the mud never in competition.
Any help or suggestions would be greatly appreciated.
thanks

[75K30]

I like Fords, and I like the C6 This is a bulletproof transmission that was designed to take some abuse.

I use TransGo products, and unless I run a full manual valve body, I would use a stage II shift kit.
If the trans will get a re-build along with this kit, I would also make sure that I used the largest intermediate servo possible. Locking the intermediate band will with as much force as possible will provide ample grip on the drum. Early 428 Cobra C6's used this large servo.
Then a real must is a sometimes difficult to install roller clutch. I hit each of my friction plates (steels) with 600 grit sandpaper before they go in. The same is true for the drum.
I also make sure that the governer is new, or has a machined surface to guarantee a leak free and trouble free operation. This governer is responsible for regulating valve body pressure and is what can make or break this transmissions ability to upshift with some snap. Low pressure due to a small leak will create a soggy upshift and make your shift kit vitrually worthless.
MAke sure you have no leaks here, and your trans will shift like a champ.
UPgrade the u-joints on the 9 inch axle, because with solid shifts and 35's being motivated by a BBF, you can plan on barking the tires under heavy acceleration. This can take its toll on consumable parts.
Sounds like fun. Any pics????

[56 Ford]

When wwe had the engine apart we rebuilt the transmissionwith the standard kit. I ordered the kit from a local transmission shop, he didn't tell me that we could add extra clutches, just wanted to make quick bucks. put in new sprag. cleaned and reinstalled governor but didn't think to check for flatness. the servo piston nor replacement seals for servo came with kit. maybe a good idea to replace that too? thank for the info so far. I'm still listening! Any #'s for that servo kit?

[75K30]

Originally Posted by 56 Ford

When wwe had the engine apart we rebuilt the transmissionwith the standard kit. I ordered the kit from a local transmission shop, he didn't tell me that we could add extra clutches, just wanted to make quick bucks. put in new sprag. cleaned and reinstalled governor but didn't think to check for flatness. the servo piston nor replacement seals for servo came with kit. maybe a good idea to replace that too? thank for the info so far. I'm still listening! Any #'s for that servo kit?

A standard kit can work very well, but I still sand the steels and drum with 600 grit sand paper. If it is together already, then it is water under the bridge, and I would not hesitate to run this the way it is. A stage two shift improver kit will wake up the soggy 2 to 3 shift, and the truck will respond well to it. Line pressure will increase and you will really feel what a trans can shift like. Nice crisp shifts and none of this lazy soggy shifting.
As far as the governer is concerned, you can address this at any time really.
As far as the servo, this is where things start to add up, but you have thrown some bucks around already, so another couple of hundred wont hurt. The "R" code servo is a little rare, but can be found, and TCI makes a billet reproduction. The advantage is in the larger diameter apply piston. This thing is almost 2.5 inches. Their kit comes with a couple of apply return springs, to further tune shift firmness. I believe the part number for the TCI unit is 423005, or 432005? I dont remember exactly. Thats either too many beers, or I am getting old. Errrr, maybe a combo of both, lol.