Piston Specifications
| <Except GSI Models> | Piston Diameter (Std.)  Note: There are three standard sizes of pistons marked with a No. on top.  | No.1 | 3.1862-3.1888 | 
| No.2 | 3.1888-3.1870 | ||
| No.3 | 3.1870-3.1874 | ||
| Piston Clearance | .0024-.0031 | ||
| <GSI Models> | Piston Diameter (Std.)  Note: There are three standard sizes of pistons marked with a No. on top.  | No.1 | 3.1846-3.1850 | 
| No.2 | 3.1850-3.1854 | ||
| No.3 | 3.1854-3.1858 | ||
| Piston Clearance | .0039-.0047 |