I'm not really aware of a gap in the Mopar big block head line up. Most customers I deal with are happy with the Trick Flow 240. A few of them want to step up to MW heads so then they can choose TF270 or move to the Indy platform. The Indy platform extends up to the 900-1000 hp range with the 440-1 345 and the 572-13.

Personally I don't focus much on the 1000+ hp customers since they are so rare. I've never actually had a customer who wanted to build a 1000+ hp Mopar big block. Everyone I've worked with personally over the last 20 years has been shooting for something in the 600 to 900 range and there are well proven combinations that cover that power range.