I want to put 10.5 and 9" wheels on my 99. Does anybody know of any clearance or other issues I might encounter? 277/40/17 on the back. 245/45/17 on the front. Thanks.

 

277? I guess that's a misprint and you meant 275's. Anyways you should be fine assuming you get the right wheels with the right back spacing. I have 315's on the back and 275's on the front and have no issues. I'm also lowered 1.5"+

 

If you're goingwith those size tires, it would look best with a 9" wheel on the back and a 8" wheel up front.
If you put 10.5 on the rear you should go with a 315/35/17 and a 275/40/17 would be perfect on a 9" rim for the front.