I'm getting around 65gps. My biggest limiter is heads. Running peanut ports. Had a good set laying around, and wanted to see how much I could get out of some serious grinding work, so I spent hours cleaning them up. In the end, maybe gained 1 or 2 mph. Nothing left to gain with those heads, runs out of steam at top end..but out of the hole she pulls like a mac truck with a 25P. I think with a 21P she would stand straight out of the water, just before the outdrive grenaded.. LOL.. She's an '89 and i have owned her for about 12 years. Just can't seem to give her up yet.
Some background info about the company, in case you did not know. These early Powerplay boats were predecessors to company now known as Powerquest. They had to change name. There was already a Powerplay co. out of Fla. and they challenged the name and won.