Spark plugs, 3/4" reach.
Ford tractors, 1965 and newer with three or four cylinder gas or LP gas engine, models: 2000, 2100, 2120, 2300, 2310, 2600, 2610, 3000, 3100, 3120, 3190, 3330, 3400, 3500, 3550, 3600, 3610, 3910, 4000, 4100, 4110, 4140, 4190, 4200, 4340, 4400, 4410, 4500, 4600, 4610, 5000, 5100, 5190, 5200, 5340, 5500, 5550, 6600.
John Deere: 1020, 1520, 2020, 2030, 2510, 2520, 4030
Oliver LP GAS: 1600, 1650, 1655, 1800, 1850
Allis Chalmers GAS: 190, 190XT, D17, D19