go to www.redpepperracing.com and read up on the car.

you said it was carbeurated, making it PRE-OBD as in, no on board diagnostics. most of these guys are not familiar with these cars, and are giving you misinformation. You can swap in the D16A1 from a 86-89 Integra fairly easily, but you will have to do a manual conversion. I just so happen to have had about 7 of this generation cars, so I have a motor in my garage that will directly bolt in and is carbeurated as well. I rebuilt it about 2 years ago for my last 1G CRX and never even fired it up because a drunk drver hit my car, PM me if you are interested in it, and a little more info on these cars. Either way, go to the website I directed you to and learn about these. It will get you on the right path.

DO NOT buy a newer D-series, it will not fit, they don't make mounts for it. The only swap mounts they make for these cars that I'm aware of is for B-series, but you will have to swap to a manual tranny and fuel injection.