The pre 88 Crx's are not worth the time. The 88-91 ones are amazing, I have an 88 Si Turbo myself, fully built d16a6 block with forged rods pistons etc, fully worked head with crane turbo cam, oversize valves, ported over gasket n benchd, 5 angle etc, and maited to a big fat snail ball bearing .70 c/h turbo, 3.5" open downpipe, equal length manifold, etd traction bars, bfg drag radials. Just fast as ****ing shit and honestly the MOST fun Ive ever had driving a car, just made it fun to drive and fly around, nothing in my rural town had anything close, a few guys were boosted like 7-9 psi, I was boosting 15+ for 2 seasons, the car just flew, but could still stop easy with the oversized breaks and just the fact that there little tiny boxes, weigh nothing.
Hands down, this is a good deal on an 87, but the 87's and pre are shit, no aftermarket, alot of things that STOP you from making it fast ie brake cylinder MASSIVE size, carb'd so youd have to swap to efi, that sucks.
Buy a 88-91, or a 92-95 eg, most fun youll ever have if you buy quality parts and do it right the first time.
Watch out for the cops.