The port size is ideal for a 318 with a bigger than stock cam.They can handle up to .524 or so lift just with a spring change. Excellent ex port,good intake. Some guys try to balance the flow a bit better by using 1.5 rockers on the ex,if they are using a split pattern cam. I would use a single pattern as the mags just dont need more help on the ex,lol.Also have to keep in mind when selecting a cam that your going to get "free" lift and duration because of the 1.6 rockers. I think a .480 will work great..like maybe one of comps grinds..
The air gap intake is perfect for them.They have no heat X over anyways...