i'm doing a bottom end rebuild now too. when i pulled the head, i noticed the head gasket was blocking off a few of the larger coolant passages between the cylinders. some of the passages don't go into the head (N47), but a few do, and about 1/3 of those were blocked by the gasket. during the summer the engine didn't get absurdly hot though. seeing as how we both have the F54 block, i figured i'd let ya know. the gasket i was using was felpro and the new one i just bought is also felpro. oh well... good luck on the tear down. btw, the crank pulley bolt is 27mm and the cam sproket bolt is 19mm. it should be the same with yours.