Bilstein Strut part no. differences

[89turbocabmike]

I noticed that the part# for complete bilstein strut assemblies for 89 turbos is different than those for '88 and earlier year 911/911 turbo. Anyone know what the difference is. I know they are quite a bit cheaper ($300 less per pair) but,according to Pelican's listing, "limited availability"

http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_suspen_pg1.htm#item2

Thanks