I want to replace the tuning gears on my MIM Fender Jazz fretless. It played great and sounded great acoustically when I bought it. I replaced the electronics, and now it sounds great amplified. But it slips out of tune fairly fast. I know it's a delicate thing replacing tuning gears because of the impact their weight has on balance and dead spots and whatnot. I don't want to mess with any of that; I just want the thing to stay in tune better. What should I get?