Out with the 340 & in with the 410 stroker!

You need to determine what net valve lift you plan on running, rpm, duration, compression, overall valve speed, induction, exhaust limitations, and rpm range before you can port the head for the best results.
If you really want good flow characteristics at high lift AND velocity profile, then you will push the casting to it's max in every port which takes using a sonic tester and TONS of time. But for as long as the casting holds out you can make incredible power because there is so much airspeed in the stock castings.

I always figure about .100 below max lift measured at the retainer with the springs you plan on running as what the engine will see at it's best rpms (between peak TQ and peak HP).
So .650 lift cam, work the head for strong #'s and correct air speed from .550 down. If rpm is high (7000 or more) then high lift #'s take presedence over low speed flow #'s as far as quality of air.
If rpm is lower than 7000 peak, low-mid lift #'s become more important but only if you can keep the airspeed in check at .100 below max lift. Otherwise power will suffer.

SB mopars love WIDE short turns but stock castings will penalize you in a hurry. Tubing the head bolt holes is good but be carefull because water is everywhere in stock castings.

Indy's are not much better though water jacket wise.

As for valve shrouding...it can help the port flow higher lift #'s before it goes turbulent and loses flow...but before you get carried away flow the head with the intake on, block off all the ports except the port you plan of flowing and add some clay to the top of the intake where the carb sits. If the intake helps the port keep flowing more air with more lift, then you can try unshrouding a little at a time until it gets worse or you've reached the gasket line.
I've sped the air up in W2's so much that it would drop off or go very turbulent at .500 lift, like 420fps at the short turn at .500! And with the intake on, got the port to keep flowing up to .600 lift with very fast airspeed, and as long as the rpm of the engine is not going to exceed 7000rpm you'll make excellent HP and TQ.
You'll never get reasonable air speed from a stock casting AND alot of flow....not without putting holes everywhere!! LOL!!
Brian