I have procured parts and will be moving forward with the conversion as time permits. As stated in the above post, my bike is an 89 with conventional forks and I will attempt to fit 93 inverted forks. My 89 triple tree has an ID of 45mm and the seller of the triple tree for the 93 claims a 54mm ID, so this is a must change. I hope the steering stem sizes are the same, as I do not think they changed until the forks were significantly updated in 96 or 97(?), but it's hard to know for sure without parts in hand.
The brake caliper mounts looks different so I will replace the caliper, but the brake line and master cylinder show the same part number for both years and should not need replacement. Also, the axle shows the same part number between these years and will not require replacement, so the same wheel can be used, but new collars may be required to space the wheel properly.
Rick's post on points to consider when doing a fork swap was informative. It would be nice to have a cross reference chart or something to know which parts could work from 125 or 250's as well. It's hard to tell using online microfiche.
Any other opinions on the early generation inverted forks compared to conventional units?