S&S Cycle 106-5520 3-1/2",+.010", 80" HC Forged Pistons for 1978-'84 HD® OHV Engines wall decor 99-17 Twin Cam AND 86-20

99-17 Twin Cam AND 86-20 XL models

Fat Baggers 901516-B

Isolated integrated output: turn/brake output

Backing Plate: 18-201-1B

Arlen Ness 121-007

S&S Cycle 106-5520 3-1/2",+.010", 80" HC Forged Pistons for 1978-'84 HD® OHV Engines wall decor 99-17 Twin Cam AND 86-20S&S Cycle 106 5520 These 3 1 2" +. 010" bore high compression pistons fit 1979 '84 74" HD big twin engines, producing 9: 1 compression with stock unmodified cylinder heads.. The modern alloys used in these pistons, coupled with the advanced skirt profiles, allow them to be fit tighter resulting in low engine noise and long engine life. In the past, this could only be achieved with weaker cast pistons. S&S will fit these pistons to your existing