Ok, so a lot of porting work and cosmetic clean up on the 360 J heads. I am supposed to take them to the machine shop next week. Last weekend I ran into to a fella that has a set of Magnum heads from an "89" PU and he's offering them to me for supper cheap. He said I could have them checked before I buy them, so not overly concerned. I know they're a roller set up, so there's that. Cost a little more but... Better. The magnum heads have some different hole locations for water or oil whatever it it is not sure. What would I encounter trying to make these heads work on my "72" 340 block. Any help/advise will be appreciated. Thanks in advance.