[1795]

A lot depends on your engine and cam profile. I have an aggressive cam and aluminum racing heads with a Holley double pumper. We tried 36 degrees of total advance at 3,000 rpms, but the engine just roars with 38 degrees of total advance. If you are running on 91 octane I would not suggest going to 38 degrees. I am running 93 octane and that is the minimum for that much advance.

I do not run vacuum advance on my distributor. I have the MSD 6 AL with adjustable rev limiter. With the aggressive cam that I have it probably would not make enough vacuum. I do not have any problems at low rpms. You need to go back to the build sheet and see what you have. A trained ear will know where the advance should be when you are setting your timing. Make sure you find a good mechanic who understands carbureted engines without computers, they should be able to dial it in correctly.