Who knows if a stock 1987 Iroc camaro 5.0 has an open or limited slip differential?

 

Iroc's could be ordered with or without the posi traction or limited slip (same thing). The only way to know is to check the rpo sheet in your center console glove box and look for g80, that will tell you that it has a posi. Or you could jake both rear wheels in the air and then turn one wheel and if the other wheel turns the same direction that means you have a posi. And if the wheel turns in the opposite direction that means you have an open end differential. Or you could just do a burnout and see if both wheels peel.

 

It's only because I didn't think you could tell if a car has limited slip or open because I thought with limted slip only one wheel spins first and then the other kicks in.

 

Thats exactly what a Limited slip or posi does. When one wheel spins the other with lock up and give you the traction needed to lower your 0-60 times and e.t.'s.