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455 olds to th400 to np 203?

Discussion in 'The Garage' started by sseinsane, Jul 17, 2006.

  1. sseinsane

    sseinsane Newbie

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    i have an olds 455 with a th400 2wd that runs well and a np203 to put into a 83 k5 with a 305 that has the balencer eating into the timing cover. my problem is the th400 won't adapt to the 203. i think the best way around this would be to get a 4wd th400 with a dual bolt pattern, but i don't know if there is such a thing and if there was what vehicle would it be in? is there a better way to fix this problem? also the only reason i am doing this is to save the blazer from going to the salvage yard so i can't really justify putting any larg amounts of money into this.
     
  2. diesel4me

    diesel4me 1 ton status Premium Member

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    a few options..

    You could get an adapter to allow the Olds motor to bolt to a Chevy bellhousing for about 70 bucks from Jegs or Summit Racing..that would be the cheapest and easiest way out..you may hit a snag with exhaust though..an Olds uses a crossover pipe with single exhaust,which can be adapted fairly easy..I'm not sure if stock cast manifolds will "dump" in the right spot to allow dual exhaust to be made without difficulty..might not be a big deal..

    Or you could use a divorced transfer case like a Ford or Dodge NP205 ,that has a short driveshaft between the tranny and T-case..of course that means fabbing up a mount and crossmember and the short driveshaft..(which may be made from the ones that originally held it in the Ford or Dodge--and the shaft too)..then you can use the 2wd TH400!..

    The Olds motor will bolt in using the Olds 350 diesel engine mount brackets that bolt to the crossmember..I've heard Firebird mounts can be used too,from a 350 or 403 Olds motor too...it will be a lot of work,but it will be a torque monster when your done!..you'll need to move the battery and fuel line too,because the starter and fuel pump is on the "other" side,compared to a Chevy motor...:crazy:
     
  3. sseinsane

    sseinsane Newbie

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    i'll look into it.
     

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