I have a 1962 CC ski boat with a 283 v8. I have had it for 32 years. When last used it started fine but when slid into gear it sounded like a bucket of bolts out of the rear of the engine. No warning signs. The engine idles fine and runs up with no hesitation. As soon as I feather it into gear it has a hard metallic clanking sound. I have new wires and plugs as well as a new distributor cap and rotor. It is running smooth. I pulled the transmission and took it to Kalamazoo Marine. They went through it and found nothing to repair. The drive gear out of the rear of the engine seems firm and tight. Does anyone have an idea of what the noise is or what could be causing it? Help!