I have been searching for a method to utilize a non wagon engine in a wagon and keep the sls system without swapping heads...specific case is a 1980 non turbo wagon

found some possible non mb solutions to provide for an external pump configuration

BMW E23 745i TURBO SELF LEVELING SUSPENSION PUMP | eBay

BMW E24 M6 L6 635 E28 M5 SELF LEVELING HYDRAULIC PUMP | eBay

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300517744445