340 Build.

With the 4.10's, MoPars 284/.528 mechanical cam will have enough for you.
That would be 241*'s at .050 & just a tad over .500 lift with lash factored in.
You can look at other manufacturers cams with similar durations at .050.

After your heads are Done, ask for the flow numbers to determine where it stalls. You may want To look into a cam that has more lift as the heads/engine maybe able To use it.