Has anyone done this flipper upgrade on their pre or early system 11 games? Is it worth it? Pinballlife has three flipper kits with the same number, which one did you use if you did do the upgrade?

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My game is a System 9 Comet. Clay's says it is mainly for the spring wear:

"Changing to the New Style Flipper Return Spring.
Williams changed flipper return spring styles in 1992. So on system 11 games, there's a cone-shaped flipper return spring that goes over the flipper plunger. The problem with this set up was it chewed up the flipper link, and often the spring just got weak and broke from the constant contact with the flipper link.
To combat this problem, Williams made two changes. First they changed the style of flipper link to be thicker, and have a more rounded contact point. Second they stopped using a cone style return spring. The return spring was moved outside of the plunger, where it takes less abuse and doesn't chew up the flipper link."

I'm just wondering if it is as easy as the guide makes it sound, it says just drill one hole (for the spring) and the kit is a full change out replacement.