crayner, Typically cylinder sleeves are cast iron. Sometimes aluminum cylinders are chrome plated. The heads I'm familiar with are seperate from the cylinders and do not have any ports in them. The ports are in the cylinder.
If the cylinder head is a seperate part, you can make customized combustion chamber inserts like those available from PSI. (I have no connection with them) Then you can try all different compression ratios and squish bands etc.
Good Luck on your engine.