concrete wall not level, help!!!

[supadave]

Ok, I just finished insulating my 3.5' concrete walls in my basement with 2" rigid foam. Pilot drilled holes and then tap-con'd the furring in the notches in the foam. Was all set for gyproc when I noticed the wall did not appear vertically level. Sure enough, the concrete wall itself is not at a 90* to the floor in places. It is more like 100* to the floor I would estimate.
My question: How can I fix this? If shimming is the answer, what material would I need to use? Or, is 10* no big deal, should I just continue as is?
Any info much appreciated, lots of details too (you're dealing with a true constuction newb here).
Thanks.

[Rich]

Is what you will probably have to do is shim with cedar shims. If you back off the tapcons on the top of the framing (furring) and shim the tops you should be able to get rid of most of the discrepancy.
Once you get the top shimmed to where it's supposed to be you will probably have to shim a couple intermediate spots too - so when you tighten up those spots you won't have a bow in the wall (top to bottom).

[supadave]

Boy, I am starting to wish I had of just built my walls and used batting, oh well, a little late for that now I guess :( . At least I used tapcons instead of ramset, I woulda been really screwed then!
Thanks for the quick repsonse! Off to Home Depot again for me.

[Rich]

Good luck and let us know how it works out.