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Discussion Starter · #1 ·
Hopefully someone can expound on the swap of a Chevy S-Blazer/S-10 231 transfer case into a YJ. This was mentioned on a recent thread, and the local 4X4 shop says it is possible to install a S- model 231 as a direct replacement for the NP231-J jeep transfer case, followed by a Turbo 350 tranny and then a 4.3 or small blockChevy V-8. All this with no adapters. Are the shaft splines the same. What obstacles must be overcome in this installation? I have an 89 YJ with a tired 258/auto and already have several spare small block chevy engines and a 77 K-5 Blazer Turbo 350 tranny sitting around. What year S-model 231 case should I be looking for to do an engine swap in the future? Would the full size Blazer Turbo 350 work in this conversion, or will I need one from an S-model? Just like the 94 and newer Dodge truck NP231-DHD heavy duty case looks like a drop in replacement for the jeep 231 when using Mopar drivetrain components, is there a heavy duty version of the NP231 from the Chevy/GMC stables that might work better that the S-model in a small block conversion. (I'd rather stay away from adapters if possible.) Thanks in advance for your technical expertise!


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I could be wrong here, but I believe that the S series trucks never had a TH350 tranny, and I'd be unsure whether you'd need an adapter from the TH350 to the NP231. I believe all the S trucks used a 700R4 automatic tranny (the ones from the 2.8L and smaller engines have a special small bellhousing, and wouldn't work with a 4.3 or bigger engine without an adapter i think) 4.3L S trucks, I believe use the full size 700R4.


/wwwthreads_images/icons/cool.gif '79 Suburban 4x4 454, 6" lift, 35x12.5s & '85 GMC S15 4x4
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