Before putting block assy back together, be sure to use the long skinny rifle barrel brushes to clean out the oil passages, with soap and hot water, to remove metal shavings and other stuff. It would be a pity to assemble and crank it up only to have the bearings go bad due to trash being pumped through them. Where else is the stuff going to go?
Another technique you might do is to clean all the journals & bearings. Coat the journals with Machinist's Bluing. Make sure there is no foreign mat'l between the bearing and its saddle in the block. Place the crank into position in the block. Tighten the bolts. Remove the crank. Check for bluing on the bearing shells, this is where its touching (binding). As David suggested, it may be the journal radii too big. Clean the machinist's bluing from parts using alcohol and a lint-free rag.
Put crank on V-blocks and dial indicator on center bearing journal and rotate crank to check for run-out. Should be no run-out.
A '68 AMX, nice ride. Been looking for a '69 to fix.