Thread: what transmission behind your bbc?

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thinking of going with a th 400 , what does everybody run?

TH400 here. Just for the piece of mind. TH350 would work depending on how bad you abuse it. Not unheard of.

evey thing i ever had.i used a 400 with good parts. if the car is light then you could run a power glide if you start making big Tq the 350 will bust

A-883 MYC Code, which is a four speed with OD...AKA the manually shifted 700R (has the same gear ratios)

Originally Posted by pat mccarthy

evey thing i ever had.i used a 400 with good parts. if the car is light then you could run a power glide if you start making big Tq the 350 will bust

What would you recommend as a limit on torque for a run of the mill TH350?

Originally Posted by 65cayne

What would you recommend as a limit on torque for a run of the mill TH350?

i can not. but if you have a heavy car and making good tq then your going to bust it . the 350 will not hold for long i not going to tell him to use a 350 knowing he is thinking of running a 500to632 cid.i did build a engine for a heavy drag car right off he busted the 350 .they rebuilt it the trans builder and i would not give the rebuilt 350 long to exist.

Originally Posted by pat mccarthy

i can not. but if you have a heavy car and making good tq then your going to bust it . the 350 will not hold for long i not going to tell him to use a 350 knowing he is thinking of running a 500to632 cid.i did build a engine for a heavy drag car right off he busted the 350 .they rebuilt it the trans builder and i would not give the rebuilt 350 long to exist.

I agree with the points you made. I did not know he was going that big on the motor. I was thinking more along the lines of warm 396-454 street motor.

Originally Posted by 65cayne

I agree with the points you made. I did not know he was going that big on the motor. I was thinking more along the lines of warm 396-454 street motor.

well the guy i was talking about with the 350 has the same year car you have 65cayne it is all steel all there .no lite any thing bench seat colum shift iron head big block running in 11.05 last time i seen .it will go fast .. he was ripping the back control arm mounts out of the frame from the power the engine makes .the 350 will break just in front of the tail shaft and do not have a center support like the 400 to hold the main shaft from flex or hi load just a mater of time ? i think my customer car has about 10 runs on the 350 trans but is it going to last?NO

I run a TH-400... busted it once (sprag) and got rebuilt tougher. Over 400ft-lbs with a 3200lb car, TH-350 won't take it for long. Both can be rebuilt stronger but 400 can take more abuse. With a lighter car, the TH-350 could hold up well

Originally Posted by skids72

I run a TH-400... busted it once (sprag) and got rebuilt tougher. Over 400ft-lbs with a 3200lb car, TH-350 won't take it for long. Both can be rebuilt stronger but 400 can take more abuse. With a lighter car, the TH-350 could hold up well

i been there and done it busted two HD sprags in the 400 and now running the coan super sprag

Thank you for all of the input, when i ran small blocks i had a hot 383 never had it dyno'd but was easily into the 5's on horse and went thru 3 th-350's before i went to a 400 and never had a problem after that, the last time i had a th-350 built i dumped alot of money in it for it to last about 5 miles, i would never even think of doing another one when i can get a 400 built here for almost the same cost, trouble is finding a descent builder , none here will warranty there work

i might buy one allready built , from tci, or etc.

Some follow up questions for you:

What car is this going into (how heavy)?
How much power/tq will you be putting down?
What are you looking to do with it? (street, street/strip, full-on race?)

I know many of the big dog door cars at the track (9's and faster in the 1/4) are running Powerglides but I think the TH-400 is a great unit for street, street/strip and most "slower" race-only cars...

Two more cents,

-Chris

Yes it is going to be a street strip car, might see the track 3 or 4 times in a year, talking with a guy on the forum here about putting together a bottom end for a 632 with a merlin pro block, around 13-1 compression with something in the 7's for lift and have been looking at a few different heads, AFR's , Dart's etc but whatever i run is going to have at least a 340 cc intake runner and will flow a good amount, also for now going with a single dominator and might run a belt drive, not sure i really need , might just go with a chain, can't see spending a 1000 on a belt , but maybe in the future.

I have 3 candidates for cars, i have a 80 malibu 2 door, an 85 regal and a 84 monte but is in sad condition, i am building a sleeper car, nothing that looks to fancy, going to run mini tubs with ladder bars/ coilovers on a 9'' nothing too big, i want people say "GOD WHAT WAS THAT?", i am going to cage it, allready have the material just need to do it, get vacation in a couple of weeks so i think i will decide which car i am going to use and get the cage done and start working on the rear end, i do know for now i will definately have traction problems so there is not going to be a huge strain on the drivetrain, until i can tub it, but if i do it right there are people running 8's on 10.5'' tires, allready have the fuel system minus a fuel pump big enough to run this beast car shouldnt weigh more than 3300 but thats just a guess, could be a little more especially if i ran the monte but i have ruled that car out, too much work on that one

All in all it will 95% street driven which might be once every couple weeks if i am lucky, i work about 100 hours a week so not much time

Also on the hp/torque rating i have no idea , this is my first big block, have ran small blocks with smaller displacement and am tired of them, they say theres no replacement for displacement right? anybody have any ideas on how much hp/torque with my figures?