As Mike mentioned we have had max effort heads from both Porter and Modern on my A12. Both performed just about the same and both cracked. They cracked so often I had to retire the car. But my sons heads on his A12 are 6 years old with no issues what so ever and the flow numbers where not so far off if I remember correctly? I am sure Dwyane would know better. I would not trade a small amount of flow numbers for reliability.

If you want to run real fast in F.A.S.T build yourself a Hemi it will be half the cost after one years time. Don't waste your time and money on somthing that can't win! I remember someone saying that to me a few years back!

Ed