Windoze 7 may not like the post box...............
Looks like the head is not torqued. Or a incorrect/mis-installed gasket.
Yes, but to do it correctly you'll need to remove the heads and get ALL the water jackets :lol :lol
I personally don't see how you overlook this but it happened. Are the water passages on the Boss block much larger than stock or do they look the same size?
The Felpro head gaskets I used have a scalloped edge and it did not fully cover some of the water passages.