A 486

I can't say I've looked at every possibility, but with a cursory glance at the X stat to Y bonus thread, I don't see anything that would. Your best bet would be using something to use Dexterity on your Strength checks, as bull rush uses opposing Strength checks to determine success. I can't think of anything that would do this off the top of my head, however. There's also a warblade ability that allows you to use your Intelligence modifier on bull rush checks.