I made mine some 80x40 box some flat bar for bulkhead tags
Some nice half round half flat bar (too early for technicality) for end caps and some nice tube to slide into rear outrigger :)
I haven't read it all but being a mechanic I would have replaced the tyres in a axle pair regardless of front or rear but I would also have advised that the rears were out of balance in tread depth respect so could potentially wind the diff up
I would say take one on the chin this is not a...