New front end and smooth dash ?'s

[Rollinsqrbdy]

Well everybody Im wanting to put a newer front end on the 86, like one off of a 89 sub. I think. Up to what year will fit on our trucks? what price range should i be looking for one at the junkyard? Can I use my exsisting fenders or do I need to get the ones for the suburban? Also im wanting to smooth my dash, do i fill the cracks with bondo or do i need a real good dash? I know im gonna need to put down the fiberglass materials but what else needs to be done? Thanks in advance for any answers.