Triumph Piston 498 cc. 1938/1939. OHV Speed Twin +020. 63.5 mm
STD 63 mm +020
NOS
Gudgeon Pin 17 mm
CR 7:1
incl. piston rings, gudgeon pin and circlips
No. 79 - 2 Plunger Spring Top 90-4103/Pair No. 52 - 2 Spring Cover Top Outer 90-4111No. 53 - 2 Spring Cover Inner Top 90-4110BSA Plunger Spring Cover Set Top Bantam D1, D3, C10, C11, C11Gpaint not perfect