1991 Chevy Camaro

You might want to check your end-link bushings on the sway bars. When those go bad it causes exactly the problem your having. It could also be a worn transmission mount or wheel bearings. If the engine runs good and dont seem to miss, I highly doubt its a problem with the engine itself. The cheapest way to start is to try the end link bushings. It most likely could be your problem. Ive done tons of these and only 1 out of every ten werent a bushing problem. Good luck!