I think you're kinda in the wrong forum but we'll give it a shot in the dark anyway.

First identify what engine you have! It's gasoline, right? Take some pictures and compare them (using Google) with a 302 Windsor, the 351M/400, and the 460. Once ya figure that out or at least have a clue, then post your inquiry in the engine forums of FTE.

Carb pin or engine rebuild? Wow. I know which one I would try to fix first.. a carb can be as little as $25 from a wrecking yard. An engine rebuild or remanufactured engine starts around $1000 for a short block.

We can help only if you help yourself and help us understand what you have. You've got alot homework to do to provide more information.