Hastings 4.3125" Bore +.060" Over Size, Single Cylinder Ring Set with 5/64" Top Ring, 5/64" Second Ring and a First Oil Ring is 3/16".
This Hastings Single Cylinder Ring Set has a top ring manufactured from grey iron with phosphate ring surface treatment, a second ring manufactured from grey iron with phosphate ring surface treatment. The 1st oil control ring is manufactured of steel rail/stainless expansion with a chrome rail ring surface treatment.

Application Summary:

Year Make/Model
1971-1973 Buick Centurion
1973-1974 Buick Century
1964-1966 Buick Electra
1970-1974 Buick Electra
1964 Buick Estate Wagon
1970-1974 Buick Estate Wagon
1970-1972 Buick GS 455
1964 Buick LeSabre
1970-1974 Buick LeSabre
1973-1974 Buick Regal
1963-1966 Buick Riviera
1970-1974 Buick Riviera
1970-1971 Buick Skylark
1970 Buick Sportwagon
1964-1966 Buick Wildcat
1970 Buick Wildcat
1962-1965 Chevrolet Bel Air
1962-1965 Chevrolet Biscayne
1962-1965 Chevrolet Impala
1962-1965 Pontiac Laurentian
1962-1965 Pontiac Parisienne
1962-1965 Pontiac Strato-Chief
Attributes
1st Oil Groove 3/16
1st Oil Ring Material STEEL RAIL/STAINLESS EXP
2nd Groove 5/64
2nd Ring Surface Treatment PHOSPHATE
Alternate Part Number 645S.060
California Proposition 65 No
Engborein 4.3125
Hazardous Material Code N
Life Cycle Status Code Available to Order
NAFTA Preference Criterion Code B
SDR Required Flag N
Top Groove 5/64
Top Ring Surface Treatment PHOSPHATE
GTIN 00075538051251