Pull th oil pump apart and check the bypass valve as I already suggested. I drill a smallhole in the little cup and use a sheet metal screw to thread into the drilled hole and then pull the cup out with a set of pleairs, claw hammer, anything that will pry the little cup out. Make sure and remove the cotter pin first. You can tig weld or braze the hole up and reuse the same cup if and when needed, the cotter pin will hold the cup in place. Most standard non high volume and or high pressure small block Mopar oil pumps struggle to make 55 lbs revved up with cold oil, check the bypass valve