Originally Posted by forbidden
They are the 4416 heads
Aggressive complete home hand porting makes them work pretty good.
A simple flow bench test will show you where they are at.
I do a simple quick test at .400" and at the point of peak flow ( .550" lift is good)... This simple flow bench test pretty much tells the tale of the heads power potential.
I like to get the flowing over 230CFM. @28" at high lift.
If they are not ported now, get busy. The better the heads flow the better the tunnel ram will work.
You can and will get a good result with a good honest porting effort. I do.