416 (340) stroker build with LD340 intake.

Yes, I own such a modified LD340. The idea of this trick mentioned in the Mopar engines book is a leagal cheat. Many of the old rules state a dual plane intake manifold must be used but never said a thing about remaining stock or uncut.

The idea of the mod is to create an easier pathway to the runners, so the runners see the whole carb on which to draw from. The mods are to help the intake mimic the performance of a single plane. Yes, a little lose of the low end happens, but, the top end is a screamer.

IMO, and a little bit of been there done that, you will rather have a true dual plane intake on top. What ever carb you use will more than likely (though not in stone) like a divided 1 inch spacer under it.

Now concerning the 416 & stock manifolds, OUCH!
I seriously suggest a set of headers. I would look into paying the piper of a set of tti's. At 416 cubes, you WANT that engine to breath.

Please redescribe the engine specs. What exactly is in it and how it is going to be run.