Make sure that price is for an Oldsmobile 350. That sounds like a Chevy 350 price. In my opinion a fun spirited street car that most people would be happy with would be around 300hp with a 3.23-3.73 rearend depending on transmission. You can find good running Oldsmobile 350's and 403's anywhere from 200-800 bucks. For the high end the engine better be damn nice shape. Anyway I will give you a quick example of what you could do and the type of cash you could spend. If you found a nice running 350 for say 500 you could buy an intake, headers, throw a street cam in it and pretty much have close to 300hp and that or more in torque depending on what the engine power specs were before. You would have probably a total of 1000-1200 into the engine with the above mentioned parts. You may want to buy an aftermarket carb, in that case a simple Edelbrock 600cfm would work just fine and cost you 100 bucks or less used. They are everywhere by the way. You dont sound like your going for major horsepower here so really your goal is rather simple and easy to achieve.