When I try to rev up my engine, it begins to sputter and sound like CRAP at 4K rpm. Could this be because of my completely stock exhaust? Or is there a rev limiter somewhere that I can get my dirty little hands on and adjust?
I wouldnt be trying to rev your engine above 4k in park, on an engine than is notorious for spinning bearings. Sometimes GM thinks about these things and installs safe gaurds for a reason.
if your car is a auto there is a rev limiter in park at 4000 rpms