Leaded Fuel

Your catalytic convertors cannot handle it. Your heads have hardened seats so you do not need lead additives. Besides poisoning the environment so we have an excuse for brain damaged leaders , what is your hoped for benefit?
I am (just) old enough to have run leaded in a while in a pre cat car. It likes the octane boost from ethanol mix better. And it did not show valve seat wear when it needed a high mileage rebuild, although it had the gunk in the pan. It got hardened valve seats anyway.

Hardened valve seats are only needed when an engine is expected to be run hard. Otherwise its no big deal not to replace them

100 octane racing fuel is a different story than 91-93 premium, with or without lead. The lubrication was cushion for the valve seats. If you get things gas soaked enough to make a difference on piston rings or valve stems, it will have washed the oil off and there will be big problems. Fuel lubricating things in a 4 cycle engine is a marketing myth. Octane boosters often contained lead. But lubricating the engine from the gas tank is a lie.
If you have the compression, boost or other need for octane, more often fouled plugs is the only other downside I know of.

running leaded fuel in a modern engine w the cats removed will not hurt a thing....Advance your timing.

Hemirick, I agree about any modern engine, (except for the coating on spark plugs and possible toxic build up in the pan that’s probably less with newer oils). No big deal.

adizzle- history or TMI?
As far as using something needing lead, any aluminum heads better have been made with hardened seats. Iron heads without hardened seats do eventually recede. Tests by state patrols showed exactly which hard use conditions caused the recessed seats. (A weekend cruiser/antique plate car might never be an issue if you do not go on Power Tour.) So most anything made since 1973 will have good exhaust seats from the factory for warranty length. That’s why valve jobs are not are that common by themselves on modern cars.

Gas with Tetra Ethel lead (for octane boost and valve seats) was sold from station pumps much longer than that. I am surprised the EPA let’s it be sold now
at any octane rating, and am curious. Who is selling it, an aviation place, track or a speed shop?