Head flow:
Some guys were asking me what the RHS heads we sell flow so here are the #'s....
Lift Int. Ex.
100 69 58
200 141 119
300 197 161
400 241 184
500 267 193
550 271 195
600 int. port goes turbulent

What that means is even though it goes turbulent, with an intake on it pulled to .600 lift so lifting the valve to .600 will still net you more HP.

This test used a 4.030 bore and test pressure of 28".
Ex. side I used a 1 3/4 pipe and as you can see, it's damn good OOTB!