Not only does the fuel being used make a BIG difference, but so does the desired result. Is a person setting timing for all out performance or ZERO risk of detonation under all circumstances? Pretty hard to get both. I believe in 36 total mechanical, then check idle and if it’s 12-18 I’m good, otherwise I’m adjusting the advance in the distributor. Around 54 total with vacuum. I might be leaving a bit of performance on the table, but I’m not detonating.
