The ISI is sitting on Spacers (Between Stage0 & SEI Support Tubes)--D1101180 type 00 (2.830+-.005" tall).  The Spacers are bolted to the Support Tubes with one bolt at each end (torqued after ISI was landed and torqued).  The ISI is bolted to the Support Tubes sandwiching the Spacers.  The ISI has six bolts on the East (-Y) side and would nominally have 9 bolts on the West side.  This is due to the trisymmetric ISI blocking the middle three bolts on the East side with one Spring Support Post.  This ISI only has seven (7) bolts on the West Side rather than 9.  First, the ~3" tall spacer requires the use of a 5" bolt.  This length prevents the middle bolt in the run of 9 on the West side from being installed as it runs into the Corner1 Vertical Actuator.  HAM3 will also see this issue.  Further, it would appear the second hole in from the SW corner (+Y-X) of the Support Tube is stripped.  We will try to review our 12 & 13 year old records for this problem.  The Support Table was extracted by the In-Chamber Cleaning group and maybe they'll recall a missing bolt.  Otherwise, we did not wish to re-lift the ISI and remove the Spacer to inspect the hole.  So again, only 7 bolts on the West side--not standard.