First off haveing the valve set a little loose would not cause the keeper to come out. It either was not put in good or the grooves &/or keepers are wallered out. Also watch for the rocker arm hitting the retainer. Some of the rods on a 216 can be removed without pulling the head. No. 1 is one of them. Drop the piston down enough so the wristpin will clear & loosen the clampbolt slide the pin out enough to remove the rod. The crank is probably scorred though.
