The front side windows rattle a bunch in my 85 4kq. I opened up the doors and didn't notice anything obviously loose. I'm thinking that the window guides are wearing out or something.

Any suggestions?

The felt guides in the window channels do wear out. These accelerate the liklihood of the window regulators getting stressed and the cables snapping because the window won't go up straight. I have to pick a new guide up at the dealer today, as a matter of fact! They aren't cheap, I think about $80 list for just one.