1977 Mercury 1500 performance?

[Johnsonboat]

I'm going back and forth on what to do to put a motor on my boat. I have a 1977 1500 20". I will have to put an extention kit to 25".
I'm going to find out tomorrow what that will cost.
I wondering if anyone has had this motor on a center console v? At 301lbs. I would assume power to weight would push the boat but not sure. And how do you like it?
It would be a cool novelty since the boat is a '77 also as long as it runs good.

This would only be for a year or so, then I will have money"I hope" to put a newer motor on.
The motor was free and the boat cost 400 so im not doin too bad with the basics of this project.
Maybe another dumb idea but worth a shot. I appreciate your thoughts. Sorry im all over the place on my posts but im new to this internet chat cult stuff.