Few years back I tried 4.30, 4.56, 5.13. No notable difference, except that the 5.13 would turn the tire a little off the line sometimes making the car inconsistent. This was running in a 7.5 ET 1/8 mile car for what its worth. I've watched alot of guys try really deep gear hoping to shave of some ET and lower the 60 footers, only to find no gains at all.