Straight pipe will be loud as hell and piss off the neighbors. It will also be illegal and it may drone like hell at highway speeds. Try a performance muffler instead.

It won't damage the engine but you may have driveablity issues if you do that. Todays emission systems need a slight amount of exhaust system back pressure to operate properly. Before just jumping in, do some research on exhaust pipe function and form too keep the proper pressure and flow from bank to bank. GM's can sound really strange if the exhaust system is not done correctly.

If you leave the cats and O2 sensors it should run just fine. It will be loud and will collect tickets.

Thanks guys I appreciate the feedback I just had my muffler taken off yesterday it sounds pretty good any recommendations on maybe an axle back?