I have a fat suv not the sierra, trans is under warranty as is the tcase and both diffs so I can at least get another stock trans to send back to flt.

 

that helps. you can se in my mos list what it took to get my truck into the 14's on a 100 shot, but i do have 140K on mine. if you get a good tune (a must with that much spray) i think you can get it if your tranny can muster a decent shift. a shift kit will help alot and can easily be installed into a new tranny if/when yours goes. they are less than $100 and i think it would pobably be a good idea.