The ones on my shelf are all pretty decent. The ones that sere real bad we just
did not buy unless we got them on an engine. We used to go to Pomona Swap Meet
every month for 20 years. You are right if Ported they would be fine BUT with that
much core shift I would be a bit nervous about the thickness of the port walls. I guess
just do the crummy ports first and if they go thru just toss them out if you have the time. I run stock heads so I am not knowledgeable about porting. The man who said
you would never see 250 CFM is ABSOLUTELY right = Stock Xs do NOT flow that on
the optimistic flow bench in the country!!
