im thinking of buying a TJ and having a 383 chevy small block put into it... i plan on buying a conversion kit, but im worried about what i might break on the TJ? i plan on running 31's i dont have much experience what the TJ's but ill be buying one with the nv3550 tranmission... any info would be helpful, oh and motor will be pushing 400hp

 

The axles, transfer case.

 

I've got a 241 transfer case for sale. $300 and it's yours. +plus shipping if needed. I'd say the tranny will be fine, just keep a mild clutch in it. I take it's not a Rubi so start looking for at least a dana 44 rear axle and chromo axle shafts. Sounds like fun.

 

Axles and drive lines would be the starting point to address. The nv3550 transmission might be ok (definitely stronger than the 6 speed). Though there is a reason that most V8 swaps lose the stock Jeep manuals and replace them with autos. I'm guessing you will exceed the max torque rating for the tranny with your engine though.