A Chev Truck TH400 trans shift @ same RPM as BOP 400?

Discussion in 'The Garage' started by dhdescender, Aug 10, 2003.

  1. dhdescender

    dhdescender 1/2 ton status

    Aug 10, 2002
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    Qualicum Beach, British Columbia, Canada - Eh.
    I'm quite close to installing my 500cid engine into my Blazer. I know from much research that I need to use a truck torque converter inthe BOP case behind my 500.

    Right now I have 3 TH400 tranny's in my yard
    1 BOP Cadddy with fawked internals
    1 Chev TH400 for 205
    1 chev TH400 for 203

    And I'm researching weather or not I should buy a tranny in the paper. its a BOP TH400 with a Stage 2 shift kit. It was recommened to me to use the stage 2, for crisper shifts with my tire size and HP/torque. If it get this transmission, I simply have to swap tailshafts, rather than all the guts in my truck cases over to my BOP. But if its going to be shifting like a frigging racecar @ 5000rpm's I'll stay away from it as if it were the black plague.

    Now, will that BOP with the stage 2, have essentially the same internals & shift at the same RPM's as the Truck TH400's (assuming they both have a shift kit)?

  2. diesel4me

    diesel4me 1 ton status Premium Member

    Jul 24, 2003
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    I'm no tranny expert,but as far as I know the govenor and modulator are what tells the tranny when to shift depending on vacuum and speed--the shift kit may raise it some,but mostly just makes the shift firmer.I also have a caddy 500 awaiting a new home,and have read many stories on installing one on /forums/images/graemlins/grin.gifthe 500cid website.I have heard several people that have put them in K5's and other gm trucks love them.They say it hits the firewall on the drivers side,so you have to hammer the floor/cab seam flat BEFORE you install the engine!.Just a thought,if you used one of those tranny adaptors you could use the existing chevy tranny,and gain a little clearance where you need it too!.Adaptors are about 60 bucks in Jegs book--thats what I'm gonna use if my 6.2 diesel doesnt pan out!.As far as the converter I didnt know there were any difference in them,except for the stall speeds between gas and diesel,or aftermarket ones like b&m. /forums/images/graemlins/confused.gif
  3. dyeager535

    dyeager535 1 ton status Premium Member

    Dec 13, 2000
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    Roy WA
    Whats the tag on the tranny say?

    A 200-4R for instance with a big printed "CQ" on it, means Chevy, and "Q" is a relative strength indicator...Z being the strongest, A being the weakest. (So an OA tranny would be a "weak" Olds tranny IIRC)

    You can bet anything from about A-K will be a slushy shifting tranny from a car that had no better rear gears than 3.23.

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