If you are talking about just installing baffles in the headers, be careful, you will be messing with the balance and could throw off your exhaust backpressure needs severly and especially the equation for proper tuned length. This can cause a severe loss of torque/power at certain rpms.
But, it could be done. If done correctly. Try not to screw the header pipes up so you can always go back. They are big $$ to replace the header pipes.
