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TH350 or 700?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by chaka454, May 13, 2002.

  1. chaka454

    chaka454 1/2 ton status

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    Which trans should I go with, should I rebuild my 350 or swap in a 700 what are the pros and cons between those two, I know about the overdrive and I actually like it, this is my daily driver but also my offroader once in a while so what should I do? what kind of adapter do I need for the 700 to fit my 350 motor or should I keep and rebuild my TH350?
     
  2. DesertDueler

    DesertDueler 1/2 ton status

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    I would say go with a 700r4. I loved mine in my rockcrawler. The 3.06 first gear helps alot, and the OD is another plus. They are about the same strenght as th350, so I would say swap. It will bolt rith to your 350, but you need a different torque convertor, and a few other things depending on you t-case. BTW if you are interested, I have a 700r4, 208 combo complete with shifter, crossmember, rear driveshaft, tq converter, lockup etc. PM if you are interested. The combo only has 15,000 miles on it(GM certa rebuilds)

    Dan
     
  3. NITRO

    NITRO 1/2 ton status

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    this has always been an issue. depends on exactly what u r gonna b doin with it. i would say just go with the th350. or hop up to a th400 and dont worry about n e thing except for gas milage

    NITRO
     
  4. DesertDueler

    DesertDueler 1/2 ton status

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    They arent anything wrong with the newer style 700r4s. Its the old ones that didnt hold up. Any of the GM certa ones, or a good shop has the newer style, or updates them to the newer style. Then they are basically the same strenth as the th350. I know a few people that run the first gear of a 700r4 in the th350 because it is stronger and alot lower(3.06 vs. 2.52). The weak part of a 700r4 is od, other than that they are fine.

    Dan
     
  5. ChevBlazin

    ChevBlazin 1/2 ton status

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    I had my 700 replaced with a rebuilt 350 2 years ago. I really wish I had the 700. From what I hear if they are built right they are just as durable as the 350. I want the overdrive of the 700 for better gas milage. I also think the 700 has a lower first gear. My 350 is a few inches shorter than the 700 was and they put an adapter on mine to keep my drive line length the same. Tell ya what, get a rebuilt 700 and I'll trade ya for my 350 /forums/images/icons/smile.gif
     
  6. you can put 3.06 1st in a th350? the lowest i've seen is 2.75.
     
  7. LA Bogger

    LA Bogger 1/2 ton status

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    I would go with the 700R, just because of the OD and Lower 1st. No adapter is needed for the 350sbc motor or 454BBC .

    Eat More Mud!!!
     
  8. txbartman

    txbartman 1/2 ton status

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    From what you described, "daily driver and occasional off-roader", I would recommend the 700. It's really hard to beat the OD and lower first gear. Get a later model one or "reputeably" (i like making up new words) rebuilt one. If you are still concerned, add as big a cooler as you can get and maybe even a deeper pan with cooling fins.
     
  9. DesertDueler

    DesertDueler 1/2 ton status

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    A buddy of mine that builds trannies modified a th350 case to fit the 1st gear set of a 700r4. The first gear set is bigger than the th350 one so he machined the case to do it. He did that before the 2.75 gear was available, so he had to make something work.

    Dan
     

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