Blown head gasket or something else?

[Don-T]

I use a paint pen, mark the socket, place the socket on the bolt, mark the head 90 degrees from the socket mark, then hammer the bolt home (I do the heads with impact wrenches on the Cat 3500 series engines).

I finally had time to at least get the heads installed today. I used the paint on the socket and head method as you suggested but I didn’t use an impact. I used a long ratchet to get it done. It will be a week or two before I can start installing everything else.