I have a 1985 390 Sportfish and have had it for 2 years.
I have had both engines rebuilt with long blocks. 1 last year and the other this year. I also change from Rochester to Eddlebrock carbs which seem to even out the power.
It is great for hanging out on the reef. Not the most fuel...
I just purchased a 1985 390 Sport Fisherman myself. We really liked the large cockpit on it.
Does anyone happen to have the parts manual for it or any of the 390 class boats?