104+ octane booster works great with pump premium, but don't get any on your fingers--they'll stink for 2 days! My experience has been there is no way in hell you can run a true 11:1 engine on 93 octane gas without retarding the timing so far it gets sluggish--even with a 140 cam, much less a 30-30. You might get away with it with aluminum heads and sloppy blueprinting, but a true 11:1 will rattle like Grandma's false teeth in a snowbank.