400 low buck dont give a

If the machine shop put a radius on the mains and the bearings arent the right shape,it would cause a lot of friction. Lot's of lube on the mains,seat the cap and finger tighten the bolts.Rotate the crank,and remove the bolts/cap. Have a look at the pattern in the lube. It will tell you where the crank is contacting and where there is clearance.And one main at a time...