So when you flowed your heads did they not have a valve job and were they the original valves reground? or did you take the heads off used and then flow them?
They were original valves but had new exhaust seats, guides and a fresh valve job by the local NAPA. How good the valve job was perf. wise is questionable. As you probably know a good perf. valve job alone is worth several cfm.
BTW: they flowed 209 max at .450 on the int. and 146 max on the exhaust at .550
I later did some porting and polishing on them myself (I'm an amateur, not pro) and had them flowed again (on the same bench) and got them up to 251 on the intake at .550 and 179 on the exh. at .600
The J heads I referred to was a set I sold to a fellow and BJR did the flow test on them. I don't remember the exhaust #'s but they were close to the X heads. I do remember the intakes flowed 215. I should state that it was a different flow bench but the atmosphere was real close to the same time each were flowed.
