Still need help, engine disassembled the heads are open chambered but casting number says there closed
The pistons are closed chambered
Why would this engine have closed chamber pistons ????
Now I'm really confused should I just use them with the open chamber heads and if so how can I find out what compression I would have with this combo.
I can find no numbers on pistons but they have about a 2/16 - 3/16 dome on them and cannot find anything on what cc's these heads are ???

3969854 block casting

3975950 head casting

Thanks for any help !!!!