Good AC is a must for a daily driven in the South. After my 2nd R4 compressor on my 87 (v-belts) started leaking, I went ahead and upgraded to a Sanden. Already converted to 134a and installed a parallel flow compressor when I replaced the 1st R4. The Sanden 4860 is the same size as the 508, but has a GM style pad so I was able to reuse the factory hoses. Used Alan Grove bracket 119L. Fortunately I replaced my exhaust recently so getting the studs out was easy. Unfortunately the factory AC bracket is also used by the PS pump, so I swapped in an Alan Grove 402L for the PS. I did have to yank the PS pulley off to swap mounts. Much simpler design and cleans up the front end. Also makes it easier to fill PS fluid. Ended up using a 60” belt for the AC, and a 39” belt for the PS. The clutch switch is wired in parallel with the high pressure cutoff. I cut back to where it splits from the loom, sealed the black ground wire with adhesive lined heat shrink, then connected the green wire to the single green wire from the compressor. The compressor connector has an integrated ground and flyback diode. The compressor mounts farther toward the driver side, so I had to ditch the factory snorkel for an open air cleaner. Pulled a vacuum for 30 min, verified no leaks, then charged with about 2.5 12oz cans of 134a. AC blows ice cold. RPM drops only 100rpm from idle when the AC kicks on so I had to back off the idle kicker (ccc carb). While cruising, I don’t even feel the compressor kicking on, just hear the click of the clutch cycling.

 

The Sandens are great compressors. I too ditched the R4 in favor of a SD7. Literally will freeze you out of the car and you can't even tell the compressor is running (vs that power hog the R4 was).