Original Gm 425 Olds Tornado forged steel crank shaft. I assume the number 20239 on the front counter weight was from Gm. I just removed it from a 64,000 Tornado with original Gm bearings. It has been checked at machine shop and is standard rods, standard mains. No cracks welds or repairs. 1966 - 67 Tornado where the only Oldsmobile to receive forged steel crankshaft from Gm, much stronger than the 455 Nodular crank.