Did all kinds of research. Get the vintage air bracket. Also has one that swaps the wonky power steering bracket that I used. Got it from summit free shipping. Fit perfectly. Just had to paint.
Currently doing the same. After lot's of debate and research I removed the R-4 and am using a sanden. amazon has a "real" one for $240. Also used the Vintage air bracket that also replaces the clumsy power steering bracket. It's about $170 from summit. Looks like the belt is going to be 58"...
If anybody has a broken seat belt buckle cover, the cover off an old camaro 78-81 works. Son and I are working on an '83 and I have an old Camaro and noticed the shape was similar so I gave it a shot. Ordered from NPD for $12 and it snapped right on. I did take it off and painted it with SEM...