Ok this is a daft question but is there any way that the heater hoses connected the wrong way could cause overheating. I'm about to pull the heads because I'm convinced the head gasket(s) are on backwards. 351 swap so non standard heater hoses and I'm running cometics which don't have the square tab showing at the front to show gaskets on correct. I noticed heater hoses on wrong...... Clutching at straws now
Doubt it will cause an issue. . Your gasket should block the front water passages and have the rear open. .