Re: 1981 Renken Bowrider
what do you want to know? The boat is really just a bunch of wood and fiberglass glued together into a shape.
Unlike cars, the propulsion system of a boat is not made by the vehicle manufacturer. Have a look at the motor and you'll probably find a specific forum here at iboats specific to it - e.g. Mercruiser, OMC, Evinrude, Yamaha, Volvo etc...
An 81 Renken could probably be ordered with any of the major propulsion types (i/o or outboard) and brands.