Kit includes spring, piston seal, front guide with spacing and rear slip washer.
Kit drops into the gun with the long front guide spring end going in first.
Next drop the short rear slip washer on the rear guide- ( trigger end)
Moly the rear spring guide lightly and twist on the spring. Moly sold separately. Lightly heavy tar the spring OD.
This is a deluxe version of the Old School kit. Power is the same but more emphasis on reducing any vibration.
Installation is easier than factory parts as our kit is shorter but full power.
Note- If I tuned your gun I would make a kit just like this and button the piston with machined in buttons and other tweaks to the internals and piston seal etc. So this would be a base for our old Ultra Glide tune we did for many years. No longer available however.
***The old sub 10K serial number guns are better with our softer kit.
They don't make great power because of several issues.