Tire wear, what's causing this! ? ?

Because I have front end from a 73 a body . Front discs , A Arms ... etc...

i guess my question was - has any one ever done the front disc conversion from a 1973 A body to a 68... and if the idler arm and pitman arm are usually changed with this process or stocks are kept in with ... and one have any photos of 1968 A body pitman arm and idler arm so i can use for reference that . that is indeed what i have on mine... thanks!

damn it ... rock auto - return policy is only 50 days or 30.... im at 61 days.. oh well

any one need a 1973 A body pitman arm and idler arm?