Yeah, you're right d16...the intake side should be rougher than the exhaust side. I've P&P'd quite a few heads now, and the best way to learn is to take a junky head you aren't gonna use and practce on that. Also, the aluminum is very soft, so if u go at it too hard, you'll royally screw up your head. The exhaust side you can polish until u see your reflection in. I just use a fine grit roll and work my way finer until the last step, where i use a VERY fine wire wheel.