1982 115hp Crank or Prop rated

[MNhunter1]

Picked up a pair of 115hp, one a 1982 and the other a 1984, although the '82 has the '84-85 decals for some reason. My research has suggested that the '82's after serial 5829464 are actually prop rated, leveraging the 140hp block. This '82 is serial# 6007313. It still uses the older trim unit, but can anyone verify the information regarding the crank vs. prop rating change in '82 regarding the respective serial #'s?

 

[MNhunter1]

Also curious to know about this fitting that is located between #3 and #4 plugs on the '84. It's not currently connected to anything. Something to do with cooling?

 

[MNhunter1]

Feedback received has indicated this '82 motor to be prop rated and based on the 140hp block:

From (Arne Kjetil) – “Droll” https://forums.iboats.com/threads/mercury-tower-of-power-hp-question.358147/
"1982 Mercury start measuring the engine hp at the propeller, then 140hp becomes 115hp ( ARE some other minor difference too ), Mercury 115 hp engines ABOVE serial 5829464 are rated at the propeller."

The fitting in question has been identified as a pressure port for a water pressure gauge. Looks like the '82 has the same port, but with a brass plug.