When I ported my RPM heads I just keep one runner of intake, exhaust, chamber and valve job untouchable to have comparison of my porting in the same flow bench.
As John said, best flow that I found as cast on intake was 244@.600".
Some pictures:
Intake: Ported vs Cast
Chamber: Ported vs Cast
Exhaust:
On Flow Bench
Flow Chart:
'77 Brazilian Dodge Charger R/T - Street Car Footbrake, Pump Gas, SB Mopar 360" N/A 3300lbs, Leaf Spring + Assassin Bars Best 1/8 mile ET 1.50 60' / 4.31 330' / 6.73@102.54mph
