No can not be used. The PS-2 is just an optical reader with not other components. It is also wired differently. The PS-3 is a mini PCB with a comparator and other components on it that the PS-3 board does not have inherently. SO only use a PS-2 reader with PS-2 and PS-32 with adapter boards.
ForPS-3 Diesel upgrades or OEM PS-3 steam engines use the AG-0000102 tach reader Joe mentioned.
As far as tach reader brackets they are different, and the PS-3 comes in two sizes depending on whether the Flywheel is 27mm or 30mm. The Diesel kit comes with both. G
