[scotty54]

68 Sprint with auto trans and Weber sidedrafts:

The idle speed of this setup is 1100 RPM, making it impossible to set initial timing using a standard timing light.

Using the factory setting of 5 degrees BTDC at 600 RPM, can I calculate the initial timing at 1100 RPM by adding degrees based on the additional 500 RPM? Then I can use a dial-back timing light to verify initial timing.

And if I sound confused please tell me. I normally use a light to set initial timing then adjust slightly for highest vacuum. This has worked well on low compression classic V-8's.

Since I could not use the timing light, I set initial timing using vacuum alone. However a test drive revealed slower cranking and detectable pinging under acceleration, so it is too far advanced. This was all done after replacing plugs, cap/rotor, and plug wires.