Vintage go kart Azusa velocity stack fits small Mcculloch flat back carbs as well as small Tillotsen carbs .....1 3/8" base hole spacing 1" bore 2" tall......a great addition to your vintage kart .....these look new unused OEM stack and not a repop......look the part over ask questions .....shipping isUSA only USPS priority box mail with tracking and insurance ....Paypal only please