Thinking about port and polishing my heads on my silverado to get the full flow of air through my engine wondering if this is a good idea ive heard of diffrent ways of doing this like taking a sharpie to the gasket and outlining the edge of the holes, and grinding the gasket to the size of the heads holes is this a good idea??? also wondering could i lose preassure in the air flow in doing this? any ideas will help thx

 

No need to mess with the port entry, most people that do them at home concentrate on the intake rocker arm bolt "hump" that is in the runner, and just blending the bowls a bit. Just taking the casting for that rocker bolt and blending it down with the runner works well, just have to use sealant on the rocker bolts to prevent oil leaking into the runner.

That being said, I would leave port work up to the pros.

 

As cheap as CNC ported heads have become,I don't think I would chance a home porting job.The stock heads flow very good to begin with.

 

if you port your own heads, you have to be extremely careful. if you change the angle of the runner you'll more than likely lose power. my roommate did it to his supercharged grand prix, ruined it, hes on his second set now, i dont know why he doesnt just buy a damn pair of heads. either way, it will help a little bit but youl get the most out of it if you have supporting mods, headers, exhuast, etc.

 

id stay with stock heads or get CNC ported ones

BTW, the 5.3L IS NOT a 302

 

based on this quote from your sig alone...I'd leave the porting and polishing to the pro's .....look up West Coast Cylinder Heads>>>>on the right....great guy and very reasonable prices....