I am building a “76” 280z and I bought it from this guy and he said he was going to do a SR20det swap and it came with the car so I’ve been looking and I can’t find a good wiring harness for the “94-98” SR20DET so it would be very helpful if anyone can send me in the right directions to find one. 

You probably should head over to Hybridz, https://forums.hybridz.org/

That is a fairly popular engine swap and there are a number of guys there that have done it. Don't want to chase you away but Hybridz is all about engine swaps.

Thanks I really appreciate your help.