What should I use for antque cars since lead additive is not available?

I have a 1929 Raodster Pick Up, 1933 DeSoto and 1933 Olds. Years ago, we purchased lead additive for the unleaded gas. I just got the cars and the local auto parts store tells me their is nothing I can purchase. My dad restored the cars to original condition and he passed in 2001. Any suggestions?

All comments are greatly appreciated.

Greetings cyd welcome to the Forum.

I've run some pretty high octane in some of the older vehicles I've owned, but, if you want to keep it as close as possible, I'd select something that got down toward 80 if you can find it.

Shop around, call your local Fuel Vendors and see if they can refer you to a retailer who stocks low octane.

Do the best you can on that, then, you can set the timing where it won't labor knock when you're in hi gear at about 15-20MPH, and speed up.

Have a good Day !
S.W.