My 318 burns very rich, need your advice.

I was told by a man that a 600 is to big for the 318 with stock heads, is that true?
Run away from this person, run fast, run far. Find a big stick and hide behind a tree. When he comes looking for you, wack him over the head very hard. This should straighten him out some.

Seriously........

Your going to need a tuning kit from Edelbrock which contains jets, rods and springs. Start with a larger(Thicker) rod which will lean it out. The instruction manual that comes with the carb (Or downlaodable from Edelbrock.com) will show you how it's done in detail.

Start with the primary's and then move on to the secondary side. It takes alittle time to sort this out, but it is easy enough.