That crankshaft is forged steel, and it's tougher than the lips on a woodpecker! All you need to do is be sure the oil clearance between the crankshaft and the insert bearing is correct, by grinding/polishing the crankshaft journals to get a clearance of around .0015 inches. (0.04MM) If you're using 292 six connecting rods, the standard shaft diameter is 2.100 inches (53.3 MM), and the rod bearing is the same one that's used in a 350 Chevy V8. They're plentiful and cheap, and made to survive in engines that produce over three times the HP of a stovebolt engine. There is a hardening process known as "Tufftriding" which we used on full competition engines on the dirt tracks, but it's very expensive, and won't be needed on a relatively low horsepower, low speed engine like a Chevy six. Good luck with your project!
Edit: I have found that a Melling M-29 oil pump is a direct bolt-in fit to a 216 engine block. It was used in early 235 engines, and it supplies sufficient oil volume and pressure to lubricate the 216 with the 235 crankshaft and pressurized rod bearings. That is much simpler than modifying the engine for the 250/292 oil pump.
https://www.jegs.com/i/Melling/689/...62onFhQMV0jjUAR3EqQiVEAQYAiABEgIeUPD_BwEJerry
