A bit of info on a 360

Welcome aboard nice looking car.

Definitely La cylinder heads an rocker arm assembly. You could possibly remove the rocker arm assembly and look down through the head into the lifter Valley to determine if it has a roller cam.
Another thing you might do is look on the passenger side of the block and see what the date is. If it's an 89 90 or 91 there's a chance it's a roller motor.

The roller Motors are the transition Motors from the LA's to the magnums. They used roller cams but they use the LA heads with the stamp steel rocker arms. In order to do this they used a shorter push rod in them than the other Motors use both LA and roller.
Definitely looks like an 8 3/4 rearend.