If it is supposed to be a small block car, look for dual fuel lines. If so, it had to be a SS350 or a LM1 (LM1's were only made till very late december 68 to early January 69) car if small block. Look at the springs for the hood, and if it was a ss car, then there should be heavier springs for the SS hood. If not, then if the 12 bolt is original, it was a LM1. If supposed Big Block, still check the hood springs, but could have had the single fuel line for a L78 car. 396/350 and 325 will also have dual fuel lines as well as the ss350 and LM1 cars.
Good Luck!
