Type is a SD-709 or now SD7H15 (R134a). As far as specific model number for 164 24v I don't know number. The 24v compressor uses a 6 or 7 rib groove clutch pulley for one serpentine belt whereas 12v engines use wider 7x5 ribbed pulley to drive alternator with second belt. Clutch design and end cap port design for hose hook up determines what model number is. CB is end port type for 164.
Point of information: 164 compressors are all 7 pistons so 709 type. the 09 is displacement in cubic inches but not sure that the H15 means 15 cu in or not.
SD-508 was used in Series 3/4 Spiders and 86 GTV6 and Milanos (75). These are 5 pistons and displace 08 cu in.