We checked the main bearing clearance by installing all the bearings (don’t use any lube for this process!), torquing the cap, measuring the diameter with a dial bore gauge, and comparing the reading with the corresponding main-journal diameter on the crankshaft. Ours ranged between 0.0025 and 0.003 inch. The main bearing journals are 2.50 inches, which falls on the high side of what most engine builders like to see. A good rule of thumb is 0.001 inch of bearing clearance for every inch of crank bearing journal diameter.