I'm looking to swap a chevy np231 onto a jeep nv3550 5speed tranny. Does anyone know if the bolt pattern is the same between wimpy jeep tcase and the burlier chevy model? IF they are the same, what model chevys could I look for the 231 in?

Believe the spline count and bolt pattern are different, chevy should be 27 spline.

Round 6 bolt flange, all the same. I didn't know jeeps came with a NV3550. You can always swap inputs of the t-case to mate up. Chevy trannies are 27 spline for the 1/2 ton trannies and 32 spline for the heavy duty trannies.

The bolt patterns are the same but GM clocked it 90* off of what jeep did. If you are going to put a 231 behind a jeep tranny then a jeep 231 is what you need.

The S10s also had the NP231's.