Back in the days before Plastigauge we used a piece of shim stock between the rod cap and the crankshaft to check oil clearance. With a piece of .002" shim about 1/4" wide and 3/4" long between the crankshaft and the cap, remove shims until you get a firm drag when the crankshaft is moved back and forth by grabbing the flywheel. When the crank turns freely with a .001" shim, and drags or locks up with a .002", the clearance is right. This procedure is a lot faster than fumbling around with Plastigauge. Just remember to remove the check shim before moving on to the next rod!
Jerry