Originally Posted by Kai

If it's carb'ed, you're in for some good times.

Option 1 ($): 1500 block and Si head swap with a single or twin aftermarket carb, like Harry's (1stGenCRXer's) car. He's running the 1500 block/Si head with twin webber carbs and individual throttle bodies (ITB's)

Option 2 ($): JDM dual carb'ed bowntop ZC swap. Good luck finding one of those, you'd probably have to hassle an importer, prepay, and wait a couple months for them to find and ship one over.

Option 3 ($$): Convert the entire fuel system to fuel injection. This means an Si fuel tank, fuel lines, fuel pump, and all the wiring. From there, you can drop in the Si engine (D15A3,) an 86-87 Integra D16A1, a typical FI browntop ZC, or an 88-89 Integra D16A1 with plenty more wiring work.

Option 4 ($$$$): Go nuts. Complete FI convertion, then use the HAsport or similar mounts, wiring, linkage, and axles to shoehorn a B-series into it. If you're smoking the good stuff, you can leave it carburated by finding or fabricating a single or dual carb setup for the B.