Mopar Guys In CANADA..

What fuel do you guys use...meaning from the pump. Im In western Canada have option of Esso supreme 91* Shell Think its 92*and if you look you can find the Husky/Mohawk sais 94* think its ethanol blend or somethin. Im playing around with my timing initial advance total just trying to find the sweet spot. Now I have my MSD dizzy set with 18 deg mech advance innitial at16 so totals 34 been told 34* perfect for Mopar small blk. Had pre ign problems but actually seems went away with the Husky fuel but may be the stiffer advance springs will have to fill again with esso or shell, Just curious what others have found works the best. I have 10 1/2 slugs in my 340 so will ping on me if don't run good fuel and or set it properly D