Just curious. Which engine do you have in your 27? My boat is hull #80, built in 1987 (modified cabin layout, as shown in the '87 brochure in the "photo" section). My engine is a Yanmar 1GM10, with a small two blade fixed prop. The boat is much underpowered, IMHO. I can manage about 5.5 kts at 3200 rpm with a clean bottom and no wind or current.
How about yours? Year, hull #, engine, and performance?