There is a double lipped seal that is used in the newer compressors that works better than the originals.
https://www.shopcenturyautoair.com/s...2814mm%29.html That being said, you can still buy a new compressor from the original manfacturer, not a rebuild. It has all of the updates and the newer seal, and still looks and fits identical. They do not stock them, but will build you one. I bought one, took about a month to get it, and was a little over $400. Cheap insurance for the money spent on all the other parts in the system.
http://www.almaproducts.com/Transtar...ochure-(7).pdf