basically this-and readings are at valve lift-not rpm.....valve lift is same no matter what rpm.....
Numbers are CFM's (cubic ft per minute)
lift --- Intake --- exhaust
.300 --- 150 --- 108
.400 --- 171 --- 129
.500 --- 177 --- 147
these flow #'s include blending "square" edge of valve guide vs stock valve guide( which is "square" edged-this means stock flow is actaully a little less than the #'s shown here)
using .400 lift is more accurate since a stock valve lift is .386 on a 250 and .406 on a 292.....
