klowndwarf... i only know specs on my crx (90-91) Si.. but mine produces around 108-110 hp and around 100 ft lbs of torque, and of course based off the flywheel you can prolly look on ebay for a head for your rex or a junkyard. since i only know mostly about the 2nd gen rexs, i wouldn't know for sure.. i can look around a little and try to help you out

i dont know much about earlier CRXs, but did an Si have a D15 in it? mine has a D16 in it. just curious.

ISP James... good luck man.. yea the mpfi wont really matter to you if youre swapping.. so good luck on getting read of your car(s) and getting the rex :thumbsup: