An SR-20 may be a conventional head, but it is NOT a stock valve angle head and the name says so. A stock BBC is a 23* head..........and they would NOT roll them over unless it made a difference.

Now, while I DO have my doubts about that HP number claimed for a 582 conventional headed motor, even with SR-20s, as others have stated, to build a Mopar, inch for inch and power for power with a stock TYPE head.............ain't gonna happen. That SR-20 is a killer head, but you put it on a .100 smaller bore and it will kick it in the head.............hence the 4.800 bore space of the Mopar is the root of most of our issues with killer heads

Monte