*hint* it's always easier to replace the complete upper control arm as an assembly. besides red thread-locker, rust really adds to that, heat heat heat and more heat.
Gonna be 11 er 33 duuudes describin zactly how it woulda been easy if ya did x,y,and z .... sometimes its just fk'd and aint no reasonable solution ... just cussin and bleedin
that bad bushing allows the wheel to move, effecting the toe alignment. had a few vehicles in the past with no upper control arm bushings left on the passenger side. the generally floated along rattling and not wildly wearing tires at once edge, the steering angle changed as you went over rolls, bumps and ridges in the roads. meaning you had to saw at the wheel a ton. but none of them ever ate a tire edge off like that, I'm guessing there's something else wrong or got moved. not familiar with the suspension on those trucks, but still, that's very severe wear for it to only be those bushing. maybe it's very toe-out in addition(other side should be worn nearly as bad) or something is bent/chooched. take it to an alignment shop after checking everything, both in the air and at ride height, break free and clean all adjusters/alignment points for them!
I'm going to say there's something else wrong/out of alignment there, besides just the bushings shot. that is some severe wear to the inner edge, is the other side worn at all? maybe it's going toe-out due to that spent bushing floating around or also has some toe-out instead of a tiny bit of toe-in. but still not sure that's all that's wrong there.
