Re: I'm stumped, need some help (retrohasen)
1. Yes there are shims available. They can be used to adjust toe and/or camber. The reason you need them, though is either your axle or chassis is bent, or the bushings are severely worn (less likely). Bentley doesn't list shims as an available option, so a lot of racing classes don't allow their use. For street use, though, shims are acceptable. I think BSI and a few other places sell them.
2. It depends on what the sludge is. I'm gonna guess oil because you said it's around the top of the overflow tank (the highest point in the system). Any chance you have a water to oil oil cooler/heater? Also, if you flush it now, do yourself a favor and remove the overflow tank to clean it completely. A lot of sediment settles there. Once a year is far too often to need to flush the cooling system. Any chance what you're seeing is just residue you didn't get out last time?