I have a '68 Oldsmobile cutlass s with a 455 out of a toronado and a Th350 transmission with a 2200rpm stall.The carburetor is a 600cfm vacuum secondary, Edelbrock torker II intakr, headers and the original points type of distributor. My question to every one is what is the Ideal ignition timing? I have it at 10btd but I get some intermediate poping out of the exhaust and everyone is aying the I need to advance it to 12-13btd? What do ya'll recommend

 

The exhaust popping won't have anything to do with the timing. That's caused by small holes in the exhaust letting in cool air and causing rappid expansion or air in the pipes.

10° is a good place to start. With that 68 455 I really wouldn't go any farther than that on todays gas. When that thing was built 100 octane was readilly available at the pump so keep that in mind.