You have to be kidding me. Backwards? Anyway you must have the engine out of the car? If the crank is OK, with the pan side facing up and new upper bearings in the #1 and #5 position in the block, spin the crank and check the runout on the #3 bearing with a dial indicator. Should be less than 0.001" TIR. Then put the rest of the upper bearings in and plastigauge all of the main journals. A change in clearance from one end to the other typically means a line bore job. If the clearances are close, assemble all the bearings and with lube on them check how freely the crank turns. A straight crank in a straight block requires very little effort to get it to spin. BTW, the main caps are offset and will fit in the register only one way.