The front sagged about 2 inches, so now I know where to set my rear springs. One of the best products I've came across, Is a paint stripper disk from Norton.
They're good for stripping paint and bondo, and work great for cleaning, and taking off scale. With my parts I'm fabbing, usually I shape with a 40 grit flap disk, and then go over it with one of these blue pads. After that they're pretty much ready for paint. A word of caution though, If you grab an edge too hard it can rip chunks out. And I've got a variable speed grinder, and I'm not sure if a standard grinder spins faster. They say they're rated to 11,000rpm.