Yeah prety much what he said.
You can sell your tranny then buy a hydrolic b-series tranny. Thats probably the cheapest route. The you would need to swap over to obd-1. You can use your stock p-28 ecu just get it re-mapped to dohc specs. You will lose the knock sensor though (not important)...
Your better off selling your motor and buying a b16a3 or sir2 if you want a b16, otherwise it's your open to anything you want.