Looking really good. A couple of questions about your build.
What harness did you end up going with?
What vacuum source are you using for the xfer case?
Are you using the corvette fuel return? If so, did you have to do any mods to the engine fuel rail?
Was digging around on the Web and found a reference for Westar EM-8642. Seems to be made for the 88-90 model years. Maybe that'll work?
Security Check - https://www.carid.com/westar/automatic-transmission-mount-mpn-em-8642.html