New Magnum heads for 347 with Flow data

Just my $.02 from messing around with stock Magnums there were two main castings produced, one earlier that came on mostly 5.9's and some 5.2's and another later casting that became the replacement and started out mostly on 5.2's. The later casting has slightly smaller ports and combustion chambers; measuring the chambers myself the "early" casting had average volume around 66 cc while the later one was around 63 cc average.

This makes me really wish I had the means to port my Magnums before I put them on my 360 I feel like I could have made these mods myself pretty easily and picked up 20+ cfm... oh well I'll just wait till I upgrade to EQ's and port those ha