28* initial timing for a 318? How can that be?

A hot rodded engine usually needs more initial timing than a factory engine because the longer time when both the exhaust valve and intake valves are open. This often results in lower compression at idle, less well prepared and distributed fuel at idle (due to lower vacuum), and more exhaust dilution. More lead time is needed because the combustion takes longer.

Additionally, many of our cars here on FABO were made during the years (1968-74+) when retarded initial timing was used to reduce HC & CO while idling and coasting.