Even if they're "better" they still flow like a drinking straw for feeding 440+ cubes. Once I started learning about heads for other brands, stock BBM heads are pretty sad in terms of both flow and combustion chamber design. Eric Weingartner on YT ported and flowed some BBM TrickFlow 240s and he was like "yeah they're a lot better than stock but about the same as a mid-range aftermarket SBC head..." He also reviewed a set of Stealths and noted the terrible (in his opinion) chamber design of the stock heads where the valve seats have no angled ridge continuing the top seat angle for helping low-lift flow, basically like every other aftermarket head has had for the past 15+ years or more.
With that said I have a pair of Stealths myself I'm gonna have a valve seat job done with some other hardware upgrades (10 degree locks etc). I don't hate them by any means but I'm not going to deny they (and all stock BBM heads) have flaws. Also not worth getting too caught up on flow numbers and Brand X comparisons when guys like
@IQ52 are pushing 700 HP with "crappy" stock castings. There are other factors at play like is always the case with Chrysler stuff lol. Might have to do with the bottom end geometry with the high rod length:stroke ratio? Idk, still learning myself.
Wait... we were talking about a 450-hp street engine. These threads always end up like this LOL my bad...
