Wouldn't it be easier to get some wheels with the correct offset/backspacing? I'm sure there are 100s of modern 18" or 19" wheels on the market with the correct dimensions.
It's not as easy as you might think. Mostly because the offset you need in the front is not the same as the offset you need in the back with a stock rear end if you intend to run wider than stock tires. If you just want to run 225's its easy because you can use the same offset front and back, which puts the front wheels all the way out on the fender and the rear wheels up against the springs- especially on a Duster. Looks downright goofy with 7" wide rims and a 4.25" backspace and half of the rear wheel tub open with nothing in it.
17/18" wheels for the front are much easier because they use a higher offset (more backspacing), which is what most modern cars have, so there's a lot of options. The rears basically need to be zero offset with an A-body rear, which limits options to begin with. Then you have to find a set of wheels that comes in both a fairly high offset AND a zero offset in the same style.
Which is why swapping in a B body rear gets to be an advantage, it evens up the offsets you need front/back. Or you can go the spacer route. There are plenty of those aluminum spacers with built in studs being used on the track, and the only failures I've personally heard about were because of improper torquing or infrequent maintenance.
