Over bore 1,016 mm, ring thickness 1,75-2,0-4,0 mm.
When there are two different ring thicknesses on the top ring on an B21 it's safest to measure before order.

CAR MODEL YEAR ENGINE INFO
1975~ B21A, E, F 100. Rings 1,75~2,0~4,0 mm
Volvo 240 1975~ B21A/E/F 100. Rings 1,75~2,0~4,0 mm
Volvo 240 1975~ B21A/E/F 100. Rings 1,75~2,0~4,0 mm
Volvo 240 1975~ B21A/E/F 100. Rings 1,75~2,0~4,0 mm
Volvo 240 1975~ B21A/E/F 100. Rings 1,75~2,0~4,0 mm