More accurately, compound turbos.
I'm currently running a single Holset HX35 hybrid and am leaning hard toward hanging an HT3B under the 35. I don't work the truck and will not be adding more fuel than the VE injection pump can put out with the OEM 12mm head.
I've built the engine foundationaly speaking to include a majorly ported PDR head (195cfm in, 220cfm out). Said 12v head is O-ringed and held in place with A1 12mm studs. The engine has the typical high volume intake plumbing, charge-air plumbing as well as a 4" turbo back exhaust. 60# valve springs, titanium retainers and hardened keepers, blah, blah.
My current set-up moves this 6400lb brick down the quarter in 13.95 seconds.
The problem is my EGT's are Stupid-Hot at the end of the pass.
I know this may be far from HVAC&R related but this forum board is for Other stuff as well, and I figure a few of you might be towing a load with the Cummins and might have added a second spinny thing to help keep it cool.