going from a 151 to 153 and slightly smaller drivers i would say a 1.5" and your golden, moving em back this much wont really change things at all, its slightly different, but honestly you could almost pick that up with just tension in the track adjustment, but then your maxed out, i went from a 144 to a 151 with my rev by going by back 1 down and 2.5 back and going all the way back with the track adjustment. a little weird, but honeslty, i was able to take up 7 more inches in track with that adjustment, so you see how little your gonna need.