VTX1800N1

Too bad there are no 4.6L Twisted Wedge heads for the 3V 4.6L Mustang crowd. We'd be able to adapt them to our engines.
http://www.modmaxracing.com/mobile/Product.aspx?id=268

Blown Ford

Our stock heads flow nearly as well as these Twisted Wedge. And with porting they will blow them away.
Stock 3V Heads
Lift----Stock CFM------CNC Porting CFM
.100-----77.1--------------75.3
.200----147.0-------------162.0
.300----199.6-------------228.3
.400----216.0-------------273.8
.500----223.2-------------283.6
.600----224.8-------------292.9


Exhaust
Lift----Stock CFM-----CNC Porting CFM
.100-----52.7-------------46.2
.200-----97.8------------104.3
.300----120.2------------135.7
.400----138.1------------163.2
.500----148.2------------177.0
.600----153.7------------189.6

And heres the specs on the Twisted Wedge you posted above.

VTX1800N1

I didn't know our numbers were that good! I guess that's why there are no TW heads made.