I've heard the reference to a "peanut" compressor as well and came to the conclusion it applies to the Sanden SD-7B10. It's the shortest compressor I could find. I purchased one sold by Vintage Air. It's in their catalog (near the end) and shows dimensions.
I was also interested in the lower driver side mount position. I didn't find anyone that sells a kit or brackets for this. I'm putting mine on a 340 in a '67 Dart. I ended up modifying a smog pump bracket that I found on a '78 Aspen in the wrecking yard. The smog pump was on the lower driver side underneath the PS pump. The car is not together yet, so I still need to do the plumbing.
