88 to 95

[sjr56]

On the street porting is a good thing, but polished is a waste of time. On the intake you want a little turbulance to keep the fuel in suspension, and in the exhaust, if you polish, carbon will coat the ports within 3-500 miles and there won't be anymore polish anyway. You do want to smooth things out, and remove rough spots giving as straight a shot into and out of the head as possible. polishing works best on a race motor that is taken apart regularly.

I have always left a 220grit finish on the intake side and fully polished the exhaust as well as the chamber. Port size as well as shape depends on the intended outcome. Been doing heads a long time and the polish help keep carbon from sticking to the port. The polished chamber reduces hot spots and helps combustion. Not saying its necessary, but it def. does help.