The seventies is a great prototype period for modeling! Plenty of variety, especially short tracl. You had the beginings of the manufactorers chassis, Ed Howe, Pete Hamilton and the Kit Car, etc, you still had plenty of racers with OEM frames, 55-57 Chevie chassis, roll cages were getting more and more bars, multiple shocks, big tires, wide fives, fuel cells, all of that! And plenty of cool old bodies sitting on them, too!