10" drum source?

Big was 5 on 4.5" bolt circle and small was 5 on 4"...also seen as 5x4. Here's a picture of the sbp measurement on my 71 Duster-measured center to center as I didn't want to take the wheel off. If the tires off, hook the tape measure on a stud and measure to the same side of the 2nd stud over. Mine measured 3 13/16" across two studs, skipping one. If yours measures the same...that's what you got! Might put a wanted ad here on FABO...maybe someone who upgraded has a useable set. Sooner or later I'll be in your boat. Might consider going to the larger bolt pattern and/or disks all around. Lots of threads and opinions here. Good luck!