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who's running a TH350 behind a big block?

Discussion in 'The Garage' started by jhrody, May 3, 2003.

  1. jhrody

    jhrody 1/2 ton status

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    who\'s running a TH350 behind a big block?

    I am running a TH350 behind a 454, running maybe 400hp. Have a big cooler in front of the radiator and have an RV-mode shift kit in the trans. So far not a hint of problems.

    Anyone else having luck with the TH350 behind this much torque?
     
  2. RingMaster4x4

    RingMaster4x4 1/2 ton status Premium Member

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    Re: who\'s running a TH350 behind a big block?

    If it is not built I DON'T think it will last. My 427 Tall Deck is all most done eating it's 3 third TH350. But you might get lucky.
     
  3. HarryH3

    HarryH3 1 ton status Author

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    Re: who\'s running a TH350 behind a big block?

    There are more things to consider than just getting rid of heat. The parts in a TH350 are physically smaller than in a Turbo 400. Thinner shafts, smaller gears, etc. So no matter how much you cool the fluid, those items all have physical limits as to how much torque they can endure before a spectacular end to their usefulness. /forums/images/graemlins/wink.gif GM's engineeers didn't think that a TH350 would even live behind a stock 454, or they would have certainly installed the less costly TH350 in those applications. So yes, a TH350 will last for some amount of time behind a 454, but when it fails, expect it to fail suddenly, spectacularly, and without warning. /forums/images/graemlins/shocked.gif
     
  4. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: who\'s running a TH350 behind a big block?

    My '75 K5 I ran in AZ for a few years about 7 years ago had a mild 454 and built TH350 which had no problems. 454 sounds about like yours, maybe a little lower (edel rv cam, edel intake, edel w/qjet, mild head work, and smallish headers...). TH350 was built by the PO along with the 454 (only thing I did was pull an RPM and put on a Performer intake). He owned a small 4x4 shop in Deer Valley and they did the tranny, but I have no specifics. I wasn't nuts like some of these guys here, doing 4WD burnouts and such. /forums/images/graemlins/rotfl.gif but I didn't baby it too much. Though with 1/2 ton axles and 35" ATs I couldn't "get it" too much... Only other relevant point I can think of was that this thing had 3.52s so the tranny got squeezed pretty hard in there...
     
  5. Zeus33rd

    Zeus33rd Smarter than you GMOTM Winner

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    Re: who\'s running a TH350 behind a big block?

    I had a TH350 behind my almost 400hp 402...For about 3 weeks before it lost everything but reverse and first gear. That tranny lasted for years behind the old small block, but 3 weeks behind the big block. I also destryoed a TH400. Cracked the case. /forums/images/graemlins/eek.gif So now I run a 465 and have no worries. /forums/images/graemlins/thumb.gif
     

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