My 1966 14' Lund is rated for 25 and has had both a 1955 Johnson 25 and a late 90s Merc 25 on it over the years. I currently run a 9.8 Tohatsu.
Some observations:
1) with one person in the boat I would call it unsafe with 25hp. It's hyper-sensitive to steering, the weight imbalance makes skipping over waves heart stopping, and backtrolling into waves requires either a splash well, a bilge pump, or lots of bailing.
2) with a guy in the bow it's much more manageable although still touchy in a chop once you get up on plane. The boat is narrower than newer 14 footers and it shows. Backtrolling in a chop is still a water park ride.
that's my particular boat. I wouldn't put a 25 on it again although it was a thrill ride when I was younger. A smart boater would manage it fine but an inexperienced one might struggle. I learned to manage it without incident but now that I'm much older and a little wiser I know how lucky I was not to have a problem, which is one reason I stuck with a 9.8 when repowering it.