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.

700-R4 version 350 to th-350...connection?

Discussion in 'The Garage' started by 88jimmyoungowner, Jan 6, 2004.

  1. 88jimmyoungowner

    88jimmyoungowner 1/2 ton status

    Joined:
    Nov 20, 2001
    Posts:
    425
    Likes Received:
    0
    Location:
    georgia-rome
    i have a 350/350 combo and a 350/700-r4 combo. the 350 motor with the 350 tranny is blown. What do i need to do to make the 700-R4 version motor work with the 350 tranny?

    I cant seem to post in the technical forums, I guess much has changed since my last time visiting.

    BTW... the 350/350 combo is from an 81 and the 350/700 combo is from an 88. i will not be using fuel injection with the 350 tranny, i will be changing to carb for simplicity reasons.

    thanks /forums/images/graemlins/smile.gif
     
  2. R72K5

    R72K5 Banned

    Joined:
    Mar 5, 2001
    Posts:
    8,905
    Likes Received:
    0
    Location:
    central IL
    nothing, cept intake swap and flexplate swap it sounds like, if the 88 350 is still TBI and if thats what you have in the 88 now ?

    you didnt give too many details

    good luck
     
  3. 88jimmyoungowner

    88jimmyoungowner 1/2 ton status

    Joined:
    Nov 20, 2001
    Posts:
    425
    Likes Received:
    0
    Location:
    georgia-rome
    its all going into the 81, which is with the 350. we also dont want to mess with the computer stuff. simplicity is easier for novice mechanics. thanks for the answer. this is what we have guessed will work but i wanted to double check.
     
  4. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    There are a couple of differences to be aware of.

    First, the flexplates are not interchangeable between those engines. The '81 engine has a 2-piece rear main seal, while the '88 has a 2-piece. The rear of the crankshaft is different between these two engines. The flexplate on the '88 also has a counterweight that the flexplate from the '81 doesn't have. I can't recall off hand if the bolt pattern for the Turbo 350 torque converter is the same as the one for the 700R4 torque converter. You'll need to check that before going too far. If they don't match up, you can get dual-pattern flexplates that will fit 700R4's, Turbo 350's and Turbo 400's. /forums/images/graemlins/cool.gif It's been a LONG time since I did it, but to replace a 700R4 with a Turbo 400 behind my '87 'vette 350 , I had to use a flexplate from an '88 1-ton pickup with the factory Turboo 400 to get the correct bolt pattern.

    Second, the bolt pattern for the intake manifolds is slightly different. The two innermost bolts on each side are at a slightly different angle from the rest of them. A small amount of machine work on the '81 intake will let it bolt right onto the '88 engine. Or, if you plan to upgrade to a different intake anyway, I'm pretty sure that Edelbrock makes an intake for a 4-barrel carb that is designed to bolt to the TBI heads. /forums/images/graemlins/thumb.gif
     
  5. big83chevy4x4

    big83chevy4x4 3/4 ton status

    Joined:
    Mar 22, 2002
    Posts:
    6,587
    Likes Received:
    0
    Location:
    Sheridan, Michigan
    the torque converters have the same bolt pattern, as long as both are stock or a stock replacement /forums/images/graemlins/thumb.gif
     
  6. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,059
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    [ QUOTE ]
    First, the flexplates are not interchangeable between those engines. The '81 engine has a 2-piece rear main seal, while the '88 has a 1-piece.

    [/ QUOTE ]

    There, I fixed it for you Harry. /forums/images/graemlins/thumb.gif
     
  7. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    Thanks! That's what happens when you're trying to type while also trying to keep 2 small kids under control! /forums/images/graemlins/blush.gif
     

Share This Page