So here's my story...
My dad was the original owner back in the 70's. After going through two engines it has sat in his garage, not running, since '82...
Now it's my turn, in my garage...

I have the second engine, and I'm not sure exactly what's wrong with it. Other than that the floor pans need replaced, and the interior could use an overhaul. The rear right wheel will not spin, and I would like to have the exterior repainted. There are no real signs of rust, so my main initial focus will be the engine, followed by the interior.
I want more than stock power, and I'm not concerned with staying true to the internals, as long as it still looks like a Spit.
So my question is, having never dealt with the mechanics of vehicles, where would everyone start? Should I try and rebuild the engine I have with modifications, buy a rebuilt and modify, or transplant a different engine entirely?
Obviously the goal is bang for buck, and either way I'm open to all kinds of advice, and direction...
Thanks!!!
-Jon