Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Will a TH350 hold up to a big block?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 61Scout, Oct 27, 2000.

  1. 61Scout

    61Scout Registered Member

    Joined:
    May 11, 2000
    Posts:
    14
    Likes Received:
    0
    Location:
    Yakima, WA
    Getting tired of people wanting $400 for an NP203 that mates to the TH400, so now I'm wondering if I can get away with using a TH350. TH350/NP203's are a dime a dozen. Will the TH350 hold up to the Cad 472 I'm putting in? The Cad was rated at 375 hp/500 ft-lbs. from the factory in 1969. I'm keeping the engine stock. I plan on putting a shift kit in whatever tranny I do end up with. It will also be rebuilt.
    Will the TH350 hold up or am I asking for trouble? I'm doing a dual t-case setup NP203/NP205 or NP203/Rockwell T221 (if I can find one.)

    Any other ideas? If I do end up using the TH350, any specific mods I should do to it to help it out?
     
  2. ken

    ken 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,244
    Likes Received:
    0
    Location:
    Anaheim, CA
    I would say use the 350. I have had a 350 behind my 454 for 10 years with no problems in my one ton Suburban. Rebuild it and use it. I am now going to put in a 400 just because I found one for cheap. The Cad you're putting in, if its used and over 25 years old, will not be putting out those numbers that you quote, so the 350 will live. It also depends on how smart (or not) you are with the "skinny" pedal!

    ken
     
  3. k5king

    k5king 1/2 ton status

    Joined:
    Jul 23, 2000
    Posts:
    571
    Likes Received:
    0
    Location:
    Parkesburg, Pennsylvania
    i had a stock th350/203 case with a 3500 stall in a '79 full size (tank) pickup that was pretty much rusted away and just for fun i put a 1200HP. small block 400 in front of it just to play at the local mud bog!!!i'v since donated that trans to a friend and it is still running strong on the road today!!!!

    DRIVE IT LIKE YOU STOLE IT
     
  4. Blazerbob

    Blazerbob 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    214
    Likes Received:
    0
    Location:
    Western NY
    I had a th350 behind a healthy 454 in my 70 monte and it outlasted the rear end and engine. I wouldn't worry about it giving you a problem.

    <font color=blue>Blazerbob</font color=blue>[​IMG]
     
  5. getsome

    getsome 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    107
    Likes Received:
    0
    Location:
    Colorado
    I talked to a guy at the drag races a few years ago who races a 1970 cutlass(like mine)with a well built 455 and a th350 and he said that the th350 will hold up to over 500hp if you make sure to change the intermediet sprag and do sound rebuilds. The said that he went from a th400 because it takes 50hp just get the th400 moving. Just a thought.

    Getsome
     

Share This Page