I've re-tapped several race car crankshafts to a bigger thread after someone stripped the original thread trying to pull a balancer on. The balancer press bolts on tight, and uses a 1" diameter fine thread to do the pressing. Much safer, especially if there's room for an impact wrench to zip it on quickly! Fortunately, a stripped 7/16-20 thread makes a hole almost big enough to accept the next larger size tap, a 1/2"-20! All it takes is a slight enlargement of the hole before re-tapping. BTW, the same drill-tap guide I'm building for the stovebolt engines will fit the early V-8 cranks, 265, 283, and early 327, that came without the center bolt.
Jerry
