The data below is literally from the 86 - 93 Buick E Parts and Illustration Catalog:
Data from the 1988 - 1989 Front Suspension Page 6-14 & 6-15:
Front Strut (1988) (E97) = 22047983
Front Strut (1989) (E97) = 22047966
Strut Mount (1988) (1989) = 1636276
Data from the 1990 - 1991 E Front Suspension Page 6-16 & 6-17:
Front Strut (E57 6AD, 7AD) = 22064167
Front Strut (6LP, 7LP) = 22064169
Strut Mount (E97) (E57 1990 FE1) (E57 1991 6AD, 7AD) = 17999048
Strut Mount (E57 1990 FE3) (E57 1991 6LP, 7LP) = 17999499
That is all that is listed. The data is somewhat confusing to me in that I always was under the impression that the Reatta (E97) had sport suspension (FE3) for all years. The data above seems to allude any real definite specifics to my previous impressions. For what it's worth and hope it helps.