My Uncle snapped an ear of his exhaust manifold for his 49 Hudson. The repair was done with nickel rod which has now made it nearly impossible to drill thru. Luckily it doe not require and anything more than a hole for a bolt. Any tips on getting the 5/8ths hole back to where it belongs? I tried a drill press today without much luck. I'm thinking the bridgeport is the next step. Any suggestions on bits? Tungsten Carbide?