Would an extra 2" of tread width help?

I currently run 29x12x15 slicks (Hoosier) I hook pretty well, except for 1 or 2 tracks that don't have good prep. I am considering going from a 12" wide to a 14" slick, but would have to step up to 31" tire height. The tires are $100 more each. Do you think 2" more rubber on the ground would make a noticeable difference? How much do you think it would slow down my 60 ft?