S&S Cycle #106-5521 - Piston Kit - High Compression - 80" Stock Motor - +.020

These 3-1/2" +.020" 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 cylinders (when purchasing new cylinders, pistons can be fit to them as an option)

Fitment

Year(s)	Make	Model Code	Model
1936-1984	Harley-Davidson	—	Big Twin