A strange head porting question....

I'm no expert but I'll give my two cents.

Water jackets limit porting for most. They vary from head to head and year to year. Most like the J or X for the bigger valves(less money) and they flow good in stock form but they have bad exh. ports. The closed chamber 302 have small valves but you can put 2.02 in them but you can't open them up all the way or you will find water. Bottom line most great porters make the port exactly what form they want. They will use epoxy, weld whatever it takes to get the port like they want it. Basically all smallblock LA heads have the same valve spacing, port window, port height, valve angle......so just make the port look like you want it to.