I have a 68 AMX, last ran vintage as A/P since I had a 390 'plus'. Current configuration will be a 343, and be B/P. Pretty minimal differences, otherwise. Four wheel discs, 7.5" wheels, single four barrel, etc. 390 cars were classed against BB Cobras and Vettes, 343 cars ran against SB Vettes, and Shelbys etc.