The timing on my 70 w-30.

I buy leaded fuel and mix it 50% with Sunoco 94 unleaded. The leaded fuel comes from Raceway Park and is of course racing fuel. The octane rating on it is 114. Not certain if that makes the net octane 104, but it must be around that. Anyway it is the only place I can get leaded fuel.

I have timing set to factor spec now and if I recall that is 10 BTDC.

And please don't tell me the fuel is over kill.....I know.....and I know it is expensive.......but I don't mind and besides I only buy about 25-30 gallons of it all year.

 

Advance it until it knocks under hard throttle and then back it off a couple degrees. it's pretty simple.

 

X2 - ony way to do it with todays 'fuel'!!
Just use the same combo, all the time.