Few months ago I purchased a 96 and the front end would do what I think you are describing. Mine would dive a lot under braking also. I changed the oil with 4oz 10wt fork oil and balance synthetic ATF. I also cut the spring 2" and added a 2" spacer (schedule 80 pvc pipe coupler) to stiffen it up. I'm very happy with the results. If you check the recommended spring rate on the Racetech web site, stock is way to soft even when new.
All my other bikes are off road with great, modified 12+" very plush travel suspension. Hard to adjust this antique setup. Just something to consider.