We really need more info in what the class rules are.

In the open class are people running Pulling tires and unlimited drivetrain?
Give us an idea of what others are using in this open class.
The dual turbo's is probably not the way to go in pulling. Some twd run them but the blowers rule all. With turbo's once you get under them you are done. And if your truck is hooking properly you should be seeing your engine pull down.

In the class you are in now what is the HP of the other guys you are trying to run against? This would give us an idea of what you will need to make the same with the mopar stuff. I also know of a engine out there that runs the 540 class that does very well. Might be for sale.
If you are thinking of just throwing a set of PSO heads on your short block you might as well forget it. unless you find a set out there you won;t be buying a new set. Also what ever head you go with you will have to be prepared to changed pistons.

Send us some more info and we can help you out. I've been fighting to keep up with the Mopar stamp for many years in the pulling world