Small Block Cam Info - Magnum Head Swap

This is what I would do. In stages. Start with a good ignition system. Does it still retain the lean burn system? If so, dump it, convert to electronic or HEI. Put better exhaust on it. Just duals from the manifolds will do wonders. After I do that, then convert to a Performer or cast iron spread bore with either a TQ or Holley spreadbore carb. Itll run better and possibly get better mileage at it.
You are going to need to do this with any of the swaps you are talking about anyways.
Just my $.02