I worked with Jim Dove on a number of projects when I was writing for Super Ford Magazine, Mustang and Fords Magazine, and Mustang Illustrated. What Jim called 'F5' heads were the subject of an extended project of building a 390 street engine using all that we'd learned right up into the 21st Century. I had Jim cast a set of his F5 heads using the basic design of the combustion chamber from the 352-360 head and using his 'third design' exhaust runners. The 'Canadian CJ Aluminum' mentioned above is the F5, but it'll take a fair degree of work to get it to 320.
I went to Wayne Kuchtyn of 'HeadWinds' in Westland, MI., to have the combustion chambers re-worked for the latest 'heart'-shape, and the runners worked over in the manner recommended by Jim. When we were done, the Superflow showed 335 CFM at .700 lift, using a Ferrea 2.100 'nailhead' intake valve contoured per Jim's diagrams. The pockets and seats were Serdi-cut to also match the instructions.
It's all guesswork until you identify exactly what you have. Jim had the ability to mix-'n'-match various features. And he either impregnated the castings before sending them out, or was equally willing to do the impregnation after any improvement work was finished. That's what FoMoCo does. Mercedes too. And Jim was using the same impregnation equipment as the other manufacturers do.
J Bittle told me he'd seen a number of Jim's castings that had been ported until they got into the water jackets and then blamed 'porosity' for the problem. I personally watched a dyno run on an Oldsmobile engine that started gushing water to such an extent that the engine hydraulic-locked. The problem was a void big enough to stick your finger in. The heads came from Edelbrock. When you do aluminum casting, you'll get voids. It's the nature of the material. We had a large department at T&C Livonia only to do porosity repairs on C6 cases. And those cases weren't sand-cast---I believe they were injection-molded---a far more precise procedure.
KS