Don't run it anymore. Might cause further damage. Open side cover and check all lifters. Remove plugs and check them for impact damage (from any foreign debris bouncing around inside the cylinder) Turn engine by hand and observe valves moving. Try to back off all rockers to make sure you can get valve clearance, see if anything feels weird. Check springs.
Look and feel oil pan with your hand for bumps from rod bolt or something hitting it from the inside. Might want to drop the oil pan to check rod end caps and bolts.
Just some thoughts that came to mind
