I have 91 RS. I am very new with these cars so please don't get real complicated on me. This question may sound really dumb to all of you but I'm a stupid person. If i bought a chevy crate engine online. Probably a 350 or a 383. What parts would I need to replace to make sure the engine could be installed.

 

You'd need a transmission (V6 trans won't bolt up and won't hold up to a V8) motor mounts, full exhaust, full accessory drive (power steering pump, alternator, A/C, etc.), all the parts to make the crate motor run (distributor, water pump, harmonic balancer, etc), You may need a new radiator with increased cooling capacity, possibly new front coil springs as a V8 will weigh more than a V6 and drop the nose down a lot. I am sure there's more, others will chime in I am sure.