Unleaded gas & valve seats
I'm wondering about this in my 289. The engine was replaced with a rebuilt one in 1981. Don't know if the valve seats were hardened. According to Wikipedia, lead phase-out began in 1973, and disappeared in 1996. I don't recall when I started running unleaded, since I don't remember when leaded was no longer available around here (TN). Wondering if anyone can shed any light here.
I'm getting ready to do a compression test, something I should have done before doing all the work I've done on the engine (I think I was in denial after looking at what a new set of Edelbrock heads cost...). It doesn't idle all that well, but runs fine at higher rpm. Don't remember the vacuum reading when I last checked, but think it was a little low. Because of a transmission leak, the car sat for several years w/o being driven, although I did run the engine occasionally.