Cam install problem
Yep,been there on my last BB.Sometimes the block is missmachined and when they install new bearings you cant get the cam in. They can measure and hone the bearing to fit correctly but you have to take it back to the machine shop. My old shop has a selection of cams that he made cutters out of. He puts one in,spins it to cut the bearing then smoothes the bearing with a fine hone.