273 commando Build

Stroker,
I don't understand how total can only be 24* at the crank? 16+18 = 34. If vacuum is added, it will be even more. What is an fob plate? Do you use a dial-back timing light to see advanced timing? What am I missing? Is the timing not additive?

A page from a Sun manual specifies: 10* @ 500rpm (vac disconnected); 11-15* Centrifical only @ 2500 rpm; and 28-38* total @ 2500 rpm, at the crank, for a 273 w/ 4 barrel.

Does your carb have adjustments available, other than the jets?

Don't you read your plugs, or do you go by how it runs and performs?

Thanks, Richard
no other carb changes but 2 sizes smaller on jets .