The 37 tooth sprocket showed up today
I quickly slapped the vacuum gauge on the bike so I could try and get some indication of where the peak efficiency mph was before doing the swap, LOL, it wouldn't break 5 inches, it was pretty worthless as a gauge with only a single 125cc cylinder attached to it, bouncing like crazy at idle.
Oh well, the proof will be in the pudding hopefully. Gotta figure out some kind of mpg gauge for these carbureted vehicles.