Exactly how i was going to put it Cjbiagi, also note that the upper control arm bushings press in and out extremely easy (i used a old OTC ball joint press to do my left upper control arm, but i forgot to bring it back to the garage on my next work day so i used a large socket and the bench vise to remove and install the right side one's). I find that the eccentric upper bushings is the easier way out of this situation. here is a link to a set on e-bay(very good price)
http://www.ebay.com/itm/1975-80-BUICK-O ... 7483587926If in fact you do have frame spread, There are a couple of things you can do, from my own experience on my old 73 gt i had to remove the k member and make my own, i simply welded L brackets to the lca area and drilled a hole in each side and used rod and rod ends, basically replace the k-member with rod and rod ends so i could pull the front end back into place, at the time it was a very inexpensive way to make sure it stayed that way.
Now if the spread is higher up you could always make some kind of brace possibly from right above the upper control arm mounts, make sure it has a good arch to clear your engine.
The best thing i could tell you is to use your imagination, take some measurements and pictures of any area's you may need to modify then sit down with a pencil and some paper and you will surprise yourself with what you could come up with, there are so many products out there that could help you achieve what you are looking to do.