red is right. Go for the sas, and do your axles and gears at the same time.
Its easier to work on the axles if they are placed on the work bench...

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Yeah but its still not hard to do the axles and gears. Get 2 maybe 3 people on it and you could have it done in a couple hours. I know I will help him and im sure a couple other people will also, so he shouldnt have a problem with that.

I say tires first. Itll look goofy without them and like he said his are balding and whats the pint to have a capable rig if you cant even use it because your slipping all over the place? Im pretty sure he wants to be able to wheel it when its done and with nice good tires youre able to do so.