I replied in another thread, but thought I'd reply here too if anybody is looking at this thread: if your taking the weight from the "model" page on this website, those weights come from the official Chris Craft brochures. In some years they listed the weight with engines, and in others they listed the weight without engines. So, for example, the 1985 brochure lists the 312 as weighing 4445 lbs with then engines weighing up to 2588 lbs depending upon the engines ordered. In the 1988 brochure, they listed the 312 as weighing 7256 lbs - I assume that is with the engines as they don't break out the weight of the engines in the brochure.
Han.