240-300 head question

I checked the search and the other ford-6 forum and cant find what I am looking for. Does anyone know the chamber size of the old 240 and a newer 1992 300? Also the 300 seems to have monel valves but they are a different length than the 240. The 240 valves have a slight attraction to a magnet, the 300 valves don't.
Mod I posted in the wrong section. Could you please move to the E-Van section, thanks