[oil pan 4]

On lean burn you only melt pistons and damage stuff if you don't know what you are doing.
All that happens at wide open throttle.
I had a v6 camaro that had a bad IAT that caused it to run lean all the time. It had burned valves and scorched pistons.

I ran a lean burn tune for cruising for 9 months. I had it running 18:1 at idle, 16:1 for cruise, 14:1 for mild acceleration and 13:1 flooring it, with a carburetor and aem wide band O2 meter. I was able to get 10 to 20% better fuel economy with no loss in power.
Where is the down side?

Then I tore the engine down, because it had a leaky head gasket, the head gasket was leaking long before I attempted lean burning. No burned exhaust valve or damaged pistons.
So you can run lean burn as long as you don't do it by tricking sensors, making it run lean all the time.

All the go fast gear heads are afraid of lean burn, well pretty much because they are ignorant, don't know how to tune a fuel curve or never attempted it.
Some of these idiots will tell you that you need to be running a racing distributor (no vac advance) because you run a hopped up engine.
So anything that involves fuel economy, don't listen to them and forget everything you ever heard from them.