SC, it was your first two sentences, the 600 holley made my 318 a much better engine from idle on up.

Now to carb sizing: A Q-jet or T-quad or AVS or, for that matter, AFB or vac secondary Holley size the carb for the engine. My 169 cubic inch Mercedes hemi 6 runs a German version of a Quadrajet. The air door cures all.

Now to the boggy 318 woes: They are so very easy to overcam! A 340 cam is about two sizes too big for a garden variety 318. A stock 360 cam will probably be all right, one step up is even better, like the 204/204 @50 lift 0.425 valve lift 110 LSA cam you used to be able to buy from Comp.

Now to finalize the head scene: Yes, 318 LA heads are woefully puny, good for max 270 hp stock. The latest LA 318 heads, like the 302s, are worth using especially if you can port them yourself. Use the thin composition head gaskets. But if you are starting out from scratch the Mag heads or their EQ counterparts are much more worthwhile. 360 heads flow well but their big chambers make milling necessary and that $200 or so could be better spent on some Mag heads.

I've been running my 318 on unleaded since 1984 when I bought the truck and the valve clearances haven't closed (mechanical cam) in around 70,000 miles.

To the OP: Get your engine going so you can drive it, THEN worry about additions. Otherwise, you'll get caught in the "as long as I've got it apart I might as well....." trap and $1000 later it still won't be running. I am living proof of that. Best to make a simple change and GET IT ON THE ROAD!

Happy New Year!
R.