malcolm is correct about the link set up
go with a 4 link set up, coil over shocks and a pan hard bar to keep every thing in place.
you might consider a 9in rear with a spool they make these all most bullit proof now days
they are easer to narrow the after market axels you can get any wheel...
try tuning the wire to the power setting this will give you a much better weld. to do this while welding on some scrap medal turn the wire speed up or down till you get a steady sound no poping or cracking just a steady buzz like bacon frying