I would hate to go here but I think I will just for sake of info. MM&FF did a recent article where they flowed the E7's against the p heads as well as many other manufactueres. Of course they sucked but what they found when they flowed them and then used the formula to figure potential hp they actually exceeded the figures, I would say their thinking leaned towards the way the heads flow improve hp and tq as compared to the actual flow number. They were able to make 350 hp and 400 lb ft of tq from a stroked 302 (333) using the bone stock E7's which are crap in everyones eyes. Their is a place that ports the E7's for $650 including new hardware to flow 219 intake and 151 exhaust and if you figure the stock ones flow 160 cfm+/- intake you can tell right off the bat 400hp isn't impossible from $600 investment on ported E7's. I know you could get the gt-40p's for the same money but the ported e7's would still flow better and you would require more money to port the gt-40p to flow better and if you figure $400 for initial gt-40p investment and $400 to port you just entered aftermarket introductory head pricing and if you look those ported E7's also flow better than windsor and windsor jr. heads. I know there are many ways to look at this so I will just throw it out as general information because I don't care one way or the other depends on your future goals etc. on what you decide, Later