1 fast z

Ill add my two cents in. The KA head STOCK for STOCk against an L series flows as follows. The intakes flow 254 cfm when the P90, which is the highest flowing stock for stock flows 178 cfm stock at 28" of water. Thats a 43% increase over stock. My head flows about 276, so thats 55% increase over stock. Then theres port velocity, and the valve area/ram effect that is in consideration with a 4v over a 2v. Then there is the crossflow "purge" effect that you get with the 4v head. I do have to say with almost 1800 miles on my engine with no hickups, it works pretty well. I have ridden in lots of z cars, turbo etc. And for stock boost 7 PSI which is what Im at, it pulls extremly hard, and more then I thought it ever would. I am only running 20 deg of timing on 7psi of boost also, so Im real concervitive there as well. I would compare it againts a car with 16 PSI with a GT35R turbo. I ported the head for the guy as well as tuned the car for him, and my car pulls about as hard is his Ported by Me P90. The off boost torque is pretty good also, with all of that port velocity. So it is worth it, infact I am getting ready to make another head for my NA car soon too.