[rotorwrench]

A person used to be able to purchase 80/87 for lower compression engines but those days are long gone. 100LL is one of the most stable fuels there is obviously due to it's intended purpose. It is called low lead but it still has more TEL than any normal auto fuel. I've had trouble with lead fouling on 10:1 compression aircraft engines so a person should expect some on low compression engines. It will work but it's overkill on most antique engines with low compression. The price is high and it's a PITA to buy. You won't find it an the local stop & rob.