I think this was and is and will always be the cave eat until the market catches up. W9’s flow the 290 OOTB (Or so says MoPar) The aftermarket offerings (not including MoPar) above the stock head are the rpm heads and then the brodix or Indy head. Not a lot of inbetween. Now that times are (finally) changing again for us MoPar guys, the not yet released Trick Flow heads and the recent Victor heads are filling voids.
Ma MoPar still has the W2 (260cfm as cast) & W9 (290cfm as cast) available. Finishing the head if you need to port it and valve train are the expensive draw back. That’s the price of off setting the rocker on the W2 and the W9 is very different and expensive.
Most people just freak at that prospect.