The first item is about the gauges. For dual-station boats, such as my 2667 Santa Cruz, different oil pressure and water temperature sending units should have been specified when the Mercruiser system was ordered as each feeds two gauges vs. one. As they weren’t, the results are lower than normal water temperature and oil pressure readings.
It’s been many years since I corrected the oil pressure sender issue, so I had to look up the oil pressure sending units again. Best double check yourself before ordering. Retailers don’t like having electrical parts returned.
For the single station, the oil pressure sender unit was 815425T and should be replaced with 37293T for dual stations.
For the single station, the water temperature sensor was a 97258A1 and the replacement for dual stations is specified as P/N 49734. It does work, however if you look at the picture below you can see the dual-station unit has a smaller diameter thread. I think there was a Mercruiser part number for an adapter, however I just went to the plumbing section of the local hardware store and picked up a brass fitting that worked fine. I did loosen it slightly with the engine running to bleed out any air bubbles. No fuss, no muss.

Another issue with the installation is that the upper station Shift Lever should have the Shift Lever detent parts removed. When shifting back to Neutral, you want to rely on the Lower Unit detent as it was used when adjusting all the cables back by the engine. I removed mine and then tightened the Lower Unit detent adjusting screw a small amount so that I could feel it more easily from up top.

These were just a few things I discovered while working on my boat over the years. Hopefully the information may help someone.