1. Used engines, especially JDM engines, should NEVER just be dropped in. You need do a lot of service and maintenance on the engine, or you'll be pulling it back out soon after. 2. Your car is a 96 which uses OBDII, which means you need a 96 engine. Otherwise you'll never get through the emissions line.
What's wrong with your 96 engine? You're probably better off just rebuilding it.