Yeah, Makes sense. So there are swings that have 3 swing insert fittings. The later models might have needle bearing sleeves to insert, or the black soft swing pivot material. Guess which one is easier to install. You are thinking 3 swing parts to collect instead of collecting spares for one. The F mock-up is for disc and if you run rear brake only then the stronger disc is so many feet shorter to that fender and all you need is an 1/16" of stop and there you can horseshoe the shit out of close calling data story for the rest of your left until you add 1' give or take 16" into to object you both expected to be in at some point is more or less the drum setup.

I'm thinking you are going to mock up 'Disc-UP' years, continue to model 75F up to 78K is all that disc mock. So, the swing has less mod to it? On the other hand; you, 'Drum-Down'; then there you are with dual disc (no, not that kind but), dual drumming up parts for needle, bronze, or soft material swing bearing inserts. Meaning, those are your 3 designs attacking your mod in your head think you can still do it?

Someone here might have a bronze, needle, soft bearing swing insert style swing, send in the length you need to know for your measurements; to continue or trash that idea you thought you had or are good to go with that mod.