oil pressure sending unit threads on Isuzu and high pressure

[rockycoastcruises]

I recently purchased a 1987 27' Sport. When we did the sea trial the oil pressure was 100 psi and has been that way for years according to previous owner. Everything ran fine and no signs of high pressure issues, but now that I own the boat I want to get to the bottom of the question as to the real pressure reading and is a constant 100 psi a bad thing on this engine?. I want to replace the sending unit that is located near the filter. I have the original Teleflex gauge 0-100psi. The previous owner tried different sending unit, etc. and was not able to change the reading-I'm not sure that he ever had the right one. In my quest to get to the bottom of it I want to make sure that I have the right sending unit so can anybody tell me what the threads are for the Isuzu 6BD1 engine and if possible what sending unit is meant to go with this gauge? I definitely don't want to strip any threads in the engine. One dealer said that if I used the correct sending unit for a similar Sierra gauge that it should work but not sure. I was going to use a oil pressure test gauge directly on the engine but again I'm not sure of the correct thread size adapter to use. Any help and advice would be appreciated.

[coolchange]

mine is 85 and never higher or lower over the past 600 hours (never add oil tween changes) not that that answers anything but just sayin there are others with high numbers

[rockycoastcruises]

Coolchange, thanks for the information. It is good to hear that somebody else is running higher than what seems normal and you are obviously doing it without any problems. I'm anxious to get my boat in the water next season and get a better look at what is going on once it is in the water. I think that I'm all set but I guess we'll see what happens.