Swap or rebuild?

as the saying goes, a bird in the hand is worth two in the bush. Use the engine you have. I'm sure if you do a Summit cam, intake, headers and some minor head work, you will be really happy with a 318. You know the shape of your engine? why throw money down the drain on another that has unknown issues. Build the 318 and use your spare cash on other odds and ends. It also teaches your kids to be resourceful and use whats at hand.

and a grand wont get you very far by the way unless you slowly gather the parts off here used, minus cam and lifters. and a double roller from Summit for $50. can't beat that. Just be patient and budget build the 318 using the parts you have. crackedback has a thread on how to port 318 open chamber heads to flow magnificent at home. You will probably be pretty happy with the 318. Use a very thin headgasket to bump up compression by the way. If you go completely through that 318, the pricy bits will be machining.