Technical 59A Heads on 8BA help

So I went to install my 59A heads onto my 8BA today and noticed the valve pocket in the 59A head is shaped completely different from the 8BA head. Also the piston area on the 59A head is much smaller than the piston area on the 8BA head. My question is will this affect my install, can i run these heads? Thanks Chris

both sets of heads are canadian.

 

I've never placed 59A heads on my 8BA because of what needs to be done.
This might help you out.

https://www.wilcap.com/59A heads 8BA block.pdf