Mopar Performance aluminum Commando head
How many C.I. are these heads going on? This will determine how big a cylinder head that you will need. The 177cc head will more than take care of 408, and 416 strokers when done right. Also keep in mind that the bigger the runner the higher the rpms will be and have to be turned to get HP, at the cost of low performance in the lower ranges and loss of torque.
Then if you were to have the 177cc heads and you do have to do some work to them, the ccs get bigger which now moves you closer to the 190 version with bolt down parts. Just remember that you can always take it out but you can't put it back easily, or cheaply. Then once your too big with big flow #s that now your cam is too small and you just spend more money trying to catch up.
The heads are very well worth the money spent, but I'm just saying be conservative and use the smaller heads. I believe that you'll be much happier with them.
BJR Racing