Can i put 235/75/15 tires on my 2000 blazer if 235/70/15 comes stock on it without messing anything else up?

according to my tire dealer, the answer is yes. they will install one size larger and still be safe.

the new tires size is less than a inch higher than the old size so i am going to go out on a limb and say that you will be alright. the abs system is supposed to be able to operate correctly within +/- 5% of the stock size

see it done all the time, it will be fine. Worst thing that may happen is if your torsion bars have let the front sag too much they may rub at full lock, but the torsion bars are adjustable and it's easy to fix

You're looking at about a half inch difference. It will affect pretty much nothing.

then why is mine rubbing when i turnnow i gotta go take it off thanks