Hey there BoatMon! My grandfather bought a Dan Arena Custom 21 footer in 1973, and it looks a lot like yours. We had the boat for many years, unfortunately my grandfather wasn't the best at taking care of things, so it started needing a lot of work later. Anyway we finally sold it in 2002 to a family friend after my grandfather died. I saw it just last week when the family friend brought to our family reunion. It originally had a Chevy 454 motor in it, and with the dual pipes in the back, it was the loudest boat on the lake. The family friend did a fantastic job restoring the boat, including a new 454 bored out. I don't remember the new CI, but he said it pumped out 475 hp.