well I'm thinking about bumping my timing from 8* to 10* on my 350
its got iron eagles 180/64 274 comp cam, rpm air gap, holley 600 cfm 4 barrel, and msd distributor

if i bump it up will i have to switch to 91 or can i still stay in the 87-89 octane range?

 

Timing and octane don't have anything to do with each other (people often advance their timing too far and "fix" that by using higher octane gasoline, but that's counter-productive).

Initial timing is a poor way to set the timing. With the equipment you're running, you really set the "total mechanical" timing rather than the initial. If doing that raises your initial to the point that you get starter kick-back, then you need to increase the amount of advance your mechanical system provides.

Octane choice should be made based on compression, not timing.

 

alright thanks man, talked to a friend and he said something about that so i figured i would ask