almost every time you drop a different than stock engine into your car, you need the wiring harness AND ECU (KLDE to KLZE in 2g MX6 being the only exception i know of, however the ECU still needs to be eprommed in order to get the change in performance).this is true.
I think I might just get a similar engine, rebuild it, then put it in.
Just a question, if I wanted to drop an SR20DE in, is it true that i would need a new wiring harness and ECU among other things?
yes it does smoke worse on a cold engine. It still has to get up to about 3500 till it smokes though.