Port and polish Q?

[dsmdragon]

Hey Can someone tell the best way to go about polishing up my head. Also how you might go about doing a valve job as well on a 420A motor? I know how to grind it smooth and all but when it comes to the valve part I need some info.
Also is there a no when it comes to porting it out(like something that will lose me HP)
Let me know

 

[JayRolla]

If you are going to do a port job on the N/A I would have a proffesional do it on a flow bench. You dont want to mess up the flow of the head.

 

[95blackGsTurbo]

Also is there a no when it comes to porting it out(like something that will lose me HP)
Let me know

Doing it yourself will almost guarantee this. Get it proffesionally done where someone with a bench flow tester and the proper tools can port it right. And unless you have the proper valve grinding machine and right degree stone's, you can mess up the seats as well.