On an '89 TPI 350 how much power is there to be gained by going stand alone. My buddies 350 TPI just has hedders, hedman y pipe and full 3 inch mendral with a flowmaster 40. He has a T56 behind it and 3.73 posi too. How much power is hiding just the tuning alone? What has been other peoples typical gains when doing chip burning or going stand alone.