There is a sticky post on this forum (small block tech) for porting 318 heads by 'wildcrazy'. Some of the basic info should apply to your heads too. IF you end up with cracking problems and need other iron heads I had good results with EngineQuest cylinder heads. The 360 I put them on revved very quickly and was a good performer even with a 'mild' cam. EQ makes them for magnum or LA intake manifold attachment. They are Very similar to the RHS heads that were sold in the past...I think EQ was the supplier for RHS.
just some ideas.
