The shop I play at does not have a flowbench. We do have a couple accessable, but obviously it's not free. What goes thru the shop is 40% stock rebuilds, 25% mild performance builds, 20% medium performance, local circle track, etc engines, and 15% high budget race engines. The basic "street port" as they refer to it, is $250. It sounds like Dwayne's Stage 1, bowls, throat, and opennings, but no flowbench numbers. They dont waste time porting on a set of heads that has marginal valve work done. So, add $250 for Serdi five angle valve job, plus guides if needed. The all out engines go hourly for porting, due to the cost of flowbench testing, and hand labor. I have SRs out of the box. They came with seats out of round, guides too tight, and large aluminum chips still in the port. I have out of the box eddys, with some of the same issues(no chips tho!!bonus!) The point is, when I see everyone recommending these aftermarket heads, it is very rare to see a mention of paying someone to check them out and correct them . It's always "bolt them on and go". We are constantly trying to balance between $$ and power, and 90% of the time, the $ dictates the result. I would rather have a great set of heads, for $2K, then a slightly above average set for $1200. aluminum or not. There are many guys that can do quality port work, but the higher the ability, the fewer there are that can do it. ( i am not on the level of these guys..lol) Anyway, the owner/customer must take it upon themselves to do the research and validating..Buyer beware. Personally, the "Stage" idea cant be appllied to manufacturers that dont deal in identical product. (906s from hughes, or Dwayne, or Aerohead can be apples to apples; Eddys vs. SRs vs. Bulldogs cannot IMO) Sadly, most buyers go by the manufacturers specs because that's what they have access to.