Hey all:

I got this monster truck project that needed restoring and the drive train is Chevy Blazer. The engine is a early 4.3 Vortec V-6 slightly built with cam. Holley 600 cfm double pumper, headers, etc. and the engine sounds like a 454!! I crawled under and pulled out a Buick (BOP) TH350 that was slipping with the previous owner. I was going to have it rebuilt and the more I thought about it and the more my friends said go with a Chevy TH350, the more I wondered why this BOP was used in the first place. I was thinking, 'well, if it's what they had on hand for this build'...... But then I think about the time and cost of installing the adapter plate to use a BOP instead of the common Chevy TH350. I'm still wondering why.
I can tell you that it has a Downey OFF-ROAD transfer case bolted to it, which I've since removed and checked to be a sound set-up. The output shaft has been chopped to use the mating sleeve to connect the BOP output shaft to the transfer case input shaft with an exceptional 1/16" tolerance apart. But, why the BOP?? The THM tail cone diameters are all the same. Remove the tail cone and mount the trans to the transfer case using the 4 allen bolts. I'm I thinking this BOP stuff too hard? I've located another built Chevy TH350 with 3500 stall for $800 but a friend suggested I use 1500 to 1800 stall instead.
OK, I've removed the Flywheel so I could get to and remove the adapter plate. Everything looks good for mating a Chevy TH350 up and all I need to do is take my Dremel and give the two cross members another 1/8" adjustment room, MAYBE. I just checked the adapter plate and it's 1/8" to 3/16" thick with the two nuts welded up top for the top BOP mounting holes. With my new Chevy TH350 all I need to do is lop off about 4" or so of the output tail shaft.
Considering the information I've posted, should I stop losing sleep over why the BOP was used? The SUV body about has no electronics for the trans. I guess I'm just looking for advice and reassurance that everything will hook up fine. I will try and post photos of what I'm working with. BUT, I'm so glad the drive train is Chevy since my dad started at GM in 1965 in Kalamazoo, Mich. and retired from GM in Kalamazoo just before they shut their doors for good in 1995! I even have an old cast Chevy emblem from a rear hitch embedded in the concrete floor in my shop!










Thanks for your time and advice in advance!! Scott

 

Cool looking rig! What size tires?

Not sure about the BOP trans, seems like a lot of work for zero gain

 

37's X 12.5" X 15" Here's a photo of one next to my 'roll-a-round' tires and wheels I put together to get it to fit in my garage and the smaller are the normal truck tires for factory size height..

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Man, 37s on a rig that size will be hard to get stuck