You actually need to remove 4 bolts, not 2. The two big ones that hold the cap to the block will be TIGHT- - - - -use a long handled 1/2" drive breaker bar and a 3/4" socket, but remove the two small bolts that go forward into the timing cover first or the cap won't come off. The crankshaft isn't going to go anywhere- - - -there are three more main bearings holding it up. Unless you've got a 1954 or early 55 engine with the high-mount water pump, there aren't any shims between the cap and the block to worry about. Even some of those early engines didn't have shims - - - -they were only needed if the bearing fit was too tight.
Unless you're willing to break some eggs, you'll never be able to make an omelet. Get busy and inspect that front main bearing! You're looking for score marks on the crankshaft surface, discoloration of the bearing material, debris imbedded into the soft metal at the top surface of the bearing where the crankshaft contacts it, or any other indications that there's not enough clearance for the crankshaft to ride on a thin film of oil instead of actually touching the bearing. Now, that clearance needs to be between .001" and .003"- - - -the thickness of a very fine strand of hair, to a maximum of 3 of them stacked on top of each other. That's where the Plastigauge comes in- - - - -use the green colored PG. The red or the blue will be too thick to work well.
Jerry
