You're right I can't have it down very long,my only other car is a 75 /6 Dart, and it drinks the gas. Factory rings are a $125 a hole, I don't know anybody with a bore gauge. Maybe if I look hard I might find someone with one. Yes, it is the Moble 1 that has made it last. The last time the head gasket blew I checked the rod bearing, and they checked the same as new clearance, plus here is one of the rod bearings to look at it had 370,000 when I took the picture. There was just a faint hone pattern in one or two cylinders. The reason I ask about which brand of rings are good, I haven't bought any of that stuff since the 70s. I'm trying to finish up my Road Runner is the reason I don't have any spare money.