Rebuilding my TH350, need parts help

[Dugan]

Looking to do a complete overhaul on my TH350, Im currently reading and taking notes on the Ron Sessions book. But I'm at the point of what parts to buy? I see all of these special master kits online and people also knocking these kits saying the kevlar and such is useless. Its going into a 84 monte with a 400sbc pushing about 400-450 hp that will be racing the 1/4. Was going to add the trans-go 350 1&2 kit along with a fresh kit if I cannot find a kit with a full rebuild and shift kit. Anyone have any info on what kits, or what parts to individually buy? This will be my first rebuild.

 

[KrisW]

Is this a race only car, or are you going to drive it on the street at all? The reason I ask is that nowadays overdrive transmissions are so cheap and available it doesn't make sense to start with a TH350 for a street/strip car. Even a severely abused car (like I do to mine.)

If you haven't spent any money, I'd sell the TH350 stuff and go buy a 2004R and then build THAT one up. They can be built tough enough, since turbo Buick guys run them deep into the 10's. Lots of Chevy guys like the 700R4 with that deep 1st gear for the hole shot, too.

If you are running a TH350 just for the track, I can see it. TH400 is heavier and with not as favorable a gear set. The last TH350 I did, I got parts from a place called Century transmission in California. The one part I remember specifically that he suggested was a heavy duty sprag clutch for 2nd gear. Apparently that is a commonly grenaded part at the strip. The rest of the parts you already know about, such as new steels and Kevlar clutches.

I still would drop it for the 2004R. Its the first mod I make to a G Body when I get one, regardless the application.

 

[Dugan]

Yea this is strictly for the track. Prob 11.5-12.5 car just a tues/thurs test and tune beater for now. Should I try and find a "deluxe" kit that contains the thrust washers and bushings? I hear these trans's are hard on them. And with only about 400-450 hp should I worry about INT sprag failure?

 

[Dennyboy]

I normally part together my own kits. getting the best of certain parts from different vendors. seems to work out cheaper and better in the end.

 

[Kris_84elky]

I bought a full rebuild kit from hughes out of summit racing. Also got the transgo shift kit that you mentioned. Then I found transmissionpartsusa.com and got from there a wide direct drum bushing, hardened sprag race, new roller clutches, 2 additional bushings for the sun shell gear thing ( can't remember the name, in the ron session book it talked about adding 2 more bushings to it), along with a case saver and some other parts that I can't remember. My trans has nice firm shifts now and chirps the tires 1-2 shift and 2-3 shift if I get on it. I used the medium spring from the transgo kit. The only thing I would do differently is buy this case saver http://www.ebay.com/itm/350-C-700R4-4L6 ... 2560wt_905. I just got the little one that replaces the anti clunk spring and it has a clunk or clicking kind of sound to it but read online that it is normal for it to do that. "If you use the old style "lug" that fits into the case , they are very noisy. Every time you put the car into gear they click loudly and every time you slow down and the trans downshifts to low you will hear it click".

 

[Dugan]

Theres a guy I found online who builds these for living hes going to be giving me the hardend sprag and roller clutches and all the good parts he states for 250$. If i was to do his dual flow trick, a shift kit is not needed.

www.jakesperformance.com is his site. do you think 250 is pricey?