P5007950 is a Magnum casting, 10 bolt valve covers, pedestal rockers, no provision for rocker shaft oiling. The only difference is the LA intake bolt pattern. I asked a fellow who has had very accurate MP info (I think he works for them...) if there were any iron LA type heads available and the answer is no. So if you can get your hands on the LA type heads, I would suggest you do that. I'll be reworking the 915s i have now.