Heard, Stant # 10623 chrome no locking or # 10491 locking type will work. they are vented. Or just ask for a Ford F150, 6 cylinder, early sixties gas cap. Stant #'s will be the same as above. Biff Jones 'Frogarri' '59 Bugeye 'Ole Gray' '61 AH Sprite in the "Healey Book" http://sprites2.homestead.com/