or a 6.7 with tripples.... MPD had very promising results for the short time they had tripples on their truck, and they didn't even have big nozzles on it, and no nitrous. Tuning is electronic and limitless. Modern motor, with plenty of room to grow.
Even a 6.4 with tripples has enough fuel to make big power. The 150% nozzles are hardly ever touched unless people are running tons of nitrous because it is just flat out too much fuel. Custom intake manifold with a good set of ported heads and youre well over 1000hp. A good set of twins makes 1000 with 100% nozzles. Is it Wagler that made heads for Jared Rice? I saw their duramax heads at TS, and they were impressive. I bet their 6.4 heads will be just as impressive, and the stock heads are the biggest restriction when it comes to making big power.
Sure mechanical injection has its place in high horsepower applications. But I still think the 7.3 is completely out dated.