Stage IV 2.020 intake, 1.650 exhaust, .650 beehive springs these heads will roll out past 300 cfm@28'' .650 lift for the big inch power your looking for!! VS a 1.940 intake& 1.610 exhaust and some shops run a smaller exhaust than that. and with the bigger valves it changed my CC's of the heads to 89 cc chambers and I also had the go to 4CC raised dome pistons to be able to achieve the compression I needed.

 

So Stage IV are a set of Palmer's heads? Specs sound like CVO castings.. Or are they stock castings?? Are these the same as what Dirtdobber is talking about?

 

OEM castings with a seat replacement on the intakes, Bruce.
Scott

 

Thanks Scott.