inline 6 merc questions...
 

Currently have an '83 115, runs like a champ. Came across an 86/87, that is immaculate. Any performance differences between the years?

At some point right around the time frame of the engines in question the hp rating was changed for being rated at the powerhead to being rated at the prop.I had a 1975 115 and a 20'Seacraft CC and replaced it with a 1985 115 and I don't remember any signifigant change in performance.These are very fast engines

That's what I thought about the hp rating.

I think the biggest difference between the '83 and '86 inline sixes was the integrated single ram tilt and trim on the '86... I have the '83, its got guts and runs really nice but I, if only for space considerations, would love to have the integrated trim.