Sounds that you got very lucky.
I had an old GMC pickup. I don't remember what size the engine was think it might have been like a 305. It has the fiber main large gear. Had like 6 theeth break off. Boy did the truck shake rattle and roll. It was also running hot. Did the timming chain and gear myself. Had to drop the oil pan to pull the timming chain cover. The cover had a lip that was part of the oil pan gasket.