I know the last thing you guys want to hear about is GM heads in comparison to this. I think you guys are really looking a gift horse in the mouth here though. A quick comparison of these heads to say a ported LS6 GM casting shows some very similar characteristics. That's pretty good since a 347 LS1 with those heads is making in the 500rwhp NA range now.
The 247cc port volume looks big, but is it actually? The cross sectional area of the ports @ 2.74 sq in is not that big at all, I've seen some LS6 ported castings in that cross sectional area (237cc port volume) and flow about the same or less than the Kaase heads. As far as other Ford Windsor castings you probably have a awesome head in front of you here. Extrapolating on that cross sectional area of the 185AFR (2.55 sq in) and then looking what the corresponding 2.74 sq in cross section would be gets you to 195-205cc AFR's Now take those flow numbers from the Kaase heads and compare them to 205cc AFR's BIG difference there.
As for price, I know you guys are used to cheap AFR's for bad ass heads, but in comarison to what else is out there on other engine makes and you have a dam good deal going. $620 per bare head is pretty impressive when a bare LS6 casting is about that. The bad thing is that the LS6 guys have to pay some bucks for some good porting to get them to flow what the Kaase heads flow out of the box. I just want to know what a quality head porter can do with a set of heads like this. It's going to put most ported Yates castings to shame but maybe not as good as a well ported Brodix Ford or Edelbrock Victor casting.
As for me, I would run them on anything from a 347 stroker to a 408 Windsor.
Bret
