6 Pack Issues

All good evening. Thank you for all the great advise. Will a Phenolic 1/2 spacer also assist? Might be several issues here. Can a hot ign. coil cause it? Appreciate everyone
I wouldn't think a spacer would hurt. I think though, before the spacer, I'd use those thick insulating gaskets. That way you are eliminating the gasket "sammich" and eliminating all those gaskets where leaks could occur.