YES.... if you plan on drag racing a good deal go ahead and do a set of 31 or 33 spline axles, diff and new bearings. I wish I had when I did my gears. If you do it all at once, 1. don't have to get back in there 2. if you up the power or run slicks less chance of axle breaking 3. Sounds cool to say you got 31 spline axles and diff 4. Odds are if you don't you will want to later on if you have the funds to do it now DO IT. 5. if you pay to have the work done no sense in paying 2 times for the work to be done.