back in the day when hotrodders were chasing 300 hp they were the cats meow.today 300 hp is not very much. if your building a resto . good, but if your chasin hp then go with a set of aftermarket heads.kinda like speed parts for ford v8 flat heads. in their day yeah but if you want speed in your 3 window ford leave the flathead on the stand.same with the humps.