with a 25" transom 700lbs is too much weight. If you drift in even 1ft seas you'll take water over the transom. Add 2 regular size humans (from 2018, not 1973 skinny people) in the back and you have wet feet. The newer 23's have 30" transoms, higher floors, and different weight distribution. I still would try to keep the weight under 600lbs. I helped rig a 350 zuke on a 24 silverhawk this year and it's overkill IMO. When the wind/seas pick up, you still have to slow down to 20knots. It's a lot harder to lift the azz and stay on plane when you have a larger badonkadonk.
These 23's were designed for inline 6 115's (275lbs each) and Johnrude v4 115's and 135's (271lbs). 2thristy5's didn't come around until 1976/1977.
