Maybe it's too big, but my good friend has a 1974 Donzi Doral that is 24 foot, and has twin small blocks and Volvo 270 drives. The drives are cool. Shift well. Everything works on the boat, but someone could go to town on it if they wanted.
He pulls it with a regular pick up and uses regular ramps. He bought a 30 foot cruiser. He's asking 10 grand. Most of these had single BBCs. This was has twin sbcs. Cuda said that it is rare. 10 grand.