It is time to replace the leaking GM / Harrison R4 A/C compressor (leaking out back plate seal) on my 1983 300SD beater. I know that it is far better to buy new but because of budget $ , I will have to go with a rebuilt specd on a GM vehicle to get the best price - ebay?) . Which GM models ( for what vehicle and year ) and years will fit ( and possible A/C delco part #s too ) ? Thanks

(btw - I had another post here - GM & Aftermarket A/C Compressors vs MB compressors on a Sanden switchout but never found that Sanden adapter that my friend had on his 1985 300D )