I don't drive a lot of mls per season but does the original 1969 430ci need a bottle of lead replacement additive?
Only info i found was unleaded fuel for engines compatible from 1971. And people discussing octane levels when the subject is unleaded fuel. I am not interested at the moment in octane levels just some advise/experiences about unleaded fuel for original 430 engine from 1969.
unless your running it hard and bouncing the valves off the seats it should be ok,back off the timming alittle of add some av gas to stop the pingging
If the engine is "seasoned" and is running it's original valves/heads, it's fine not to install hardened seats or use a lead additive. If it is a fresh engine or the heads were rebuilt or received a valve job without adding hardened seats, lead additive is a good idea. 1000 miles a year, I wouldn't concern myself.
You fine without additives.. Heck I've pulled heads on older boat motors valves looked fine. Worn but not burned. They did not have hardened seats..