who ever said it was stock. it has a compleat diamond eye 4in exhaust. no cats or mufflers. and it just has a cheap k&n universal airfiter. it useto not smoke when i had the cats on it.
i have a 94 gmc 6.5 that kind of studders. struggles to rev up. and the motor shakes bad . but once u get it over 2500 rpms its fine. anybody know whats going on