10 bolt UBolts
#2
Are you talking about the ones that hold the rear sway bar bracket? If so, I got mine at Home Depot. They are not as strong as the OE but have held my rear sway bar for 2 years now so...
#4
Do you have a Vernier caliper to measure the axle tubes? I didn't measure mine 'cause I just matched the new (but longer) ones to my current ones. I can't think of what I even did with the originals, now that you mention it... Is there a tech section here that mentions the stock axle tube diameter? Try a search for that?