My 318 burns very rich, need your advice.

You know. All I've used on all of my 318's. About 11 of them. I've either used a 600 cfm AFB, 600 cfm AVS, or now I have a couple of 600 cfm edelbrocks. They are literly perfect for the 318. You just need to know how to tune your carb. They do not come out of the box already that way. Just learn how to do it. Find one of these wonderful guy's or gals on here to help you out.