For #2, yeah, I thinkwill have to be. There is some variation in these trucks over the decade or so involved and the many models (Blazer, Suburban, pickups.)
#1 is more troublesome. I mean, sure, you can easily enough use flat stock along the side, drill holes and bolt it up... but it shouldn't be THAT off. You'd need like two pieces of 1/4" on each side, and that's ... a lot.
Does your bumper fit right? I ask because I don't have an '81+ truck to measure any more, so I wonder if your truck was in an accident at some point and the frame is borked.
If it was just 1/4" or so, I'd say to bolt it up and drag the frame in, but you're talking about an inch or more, so something's not right.
-- A
So I got back to looking at this again tonight and the way I see it only one bolt for the shackle mount will go through. If I drill out for the other one the bolt will disappear in the box part of the hitch. Is this what you experienced?
Unfortunately I sold that truck over five years back, so I'm working entirely from the pictures I took at the time (as posted above.)They are not welded, and if you can only get the front bolt through they will rock up and down. I also do not feel safe using the tow hooks this way. I am thinking I will send this hitch back and try another route at this point.
I would have been in the same boat, except I had bought the hitch years before for a previous truck so I couldn't return it.