is it possible to put split rear seats in an 83 Z/28 that originally had a one piece rear seat? do i need to make any modifications?

 

Yes, and... no.

But someone back me up on that.

 

you can put split rears in any f-body, but, if it wasn't equipped for them you will have to weld a pivot bar onto the driveshaft hump between the rear seat backs. one side of the seat bolts to the car with a hinge (outer sides of seats) and the other slides onto the pivot bar (inner sides of seats). it is doable but you will have to do some welding.

 

You really don't even have to weld the pivot bar in. Although it would be a tad bit ghetto if you didnt. When you would flip the seats foreward, they would not be as stable.... eh, hard to explain. But I've done it before without welding in the bar, and didnt have a problem with it.