hey whats up i got a 87 iroc and i wanna put a different rear in it and i know the ones in the grand nationals are really good and strong would it bolt up in my car

Don't know how stong a GN rear is, but I do know unless it comes out of a 3rd or 4th gen it will not bolt up.

Different design suspension, so it won't bolt up without a LOT of fabrication to the axle.

a GN rearend is a 8.5 right? should be strong. Dunno if the width is right. Would have to weld your brackets on and design a TQ arm mount.. Have fun

GN is set up for a 4 link bar system, either change rear end mounts or the car mounts.

A GN rear end is completely different from a 3rd gen Camaro rear end. It would take a lot of fabrication and engineering to make it work. If you have a GN rear end then I recommend that you sell it to a G body guy and use the money to get a better F body rear end, like a Moser or Strange 12 bolt. The GN rear end will bring pretty good money.