[Goat Blower]

The thing is, porting and polishing work really well on some iron Chevy heads, they don't make much of a difference on DSM heads, because they are so good from the factory. The only real benefit on DSM heads is cleaning up the bowl area, for which you need the valves out for, and just a very light clean up of the casting boogers on the intake ports, barely even that for the exhaust ports. Bone stock heads have gone 9's, fairly stock 2G heads have gone 8's.