Bare EQ Magnum heads vs. machining stock Magnums?

EQ's are the way to go. The guides will be tight but if your machine shop is decent this is ideal for them and you. EQ's will flow 237-238cfm as is OOTB. A stock Magnum will not crack 200 cfm totally stock. Do not hesitate to go with EQ's--they seem to make excellent power in any configuration. J.Rob