Carter Bbd leaking throttle body

If it leaks there while running, something is wrong.
If it leaks there with the engine shut off, something different may be wrong.
Fix what is wrong, and it won't leak fuel there any more.
On a 318,I have never had a problem to compensate for an air leak there.

There's nothing wrong with the 4bbl idea either as long as you also install dual exhaust with it, and a new timing chain kit. Cuz if you have a 4bbl, you are gonna use it. And with 2.76s, redline in first gear is about 50mph,lol, and if things don't go well up there and the engine has the later nylon tipped upper timing sprocket, then she could rip all the teeth off right then and there...... and that will cost you more than just the tow.