VCCA Home Forums Thread Like Summary - Octane Selector

I was explaining to a friend the procedure for setting the timing on a 216 yesterday while reviewing a shop manual with him. In his case, a 1946 1/2 ton pickup, but my question is more general. He asked me where to set the octane selector after the clamp on the distributor was tightened and I gave him some guidance. He then asked me where it says that in the shop manual? After reviewing the 1941 and 1942-1948 shop manuals and a couple owners manuals I could not find any text describing the setting. My question is not what to set it at today with modern gasoline but where can I find the original Chevrolet guidance? Various Service Bulletins maybe?

The Octane Selector is nothing more than a conversation piece these days. Since vehicles of that era were made to run on low (by today's standards) octane fuel I don't even use a timing light. Once started and warmed up I set the timing to the fastest/smoothest idle then lock it down with the OS on 0. If necessary I can retard it a degree or two using the Octane Selector. It hasn't been necessary yet.