New to site. Long time muscle car lover. Have '66 Chevy II SS, nine second street car. Also, '72 Heavy Chevy Chevelle and '87 Monte Carlo SS. Not familiar with Grand National, but have the opportunity to buy '84. I need to know what to look for to know it is an original GN. Car is pretty rough. Is there restoration parts available? Such as floor pans and interior parts. Sorry for long post. Any help greatly appreciated.