I'm assuming that you're referring to the LA318 :
Edelbrock still makes the Six Pack / 6Bbl intake for both big and small block engines .
While the 340 version would bolt-on to 318 heads , its efficiency wouldn't be as great as if it were bolted to 340/360 heads .
The reason being that the 273/318 heads' intake ports are smaller ; this creates a blockage-in-flow (turbulence) .
Other deciding factors include camshaft (you'd be fine with a stock 340 grind) and , as previously mentioned , carburetter calibration .
So , in short , the Edelbrock small block intake will fit on a 318.