parts interchangability?\'s I just acquired a '80 blazer that i am stripping for parts. There is only a couple of q's that I have about interchanging with my '87. Are the rear side glasses interchangable? the '80 has sliders with tip-out vent windows that I might want to change to my '87. Are the door glasses the same? I was told that pre '80 were thicker and wouldn't work. The '80 has a factory rear roll bar- how hard is it to get out and back in an '87? I want to strip this '80 and get it out of here, but don't want to get rid anything that I would want on my '87. Any help is appreciated.