In addition to our normal rebuild process, our High-Voltage High-Current units get two additional tweaks. The first step increases the output voltage to the injectors from 110 volts to 140 volts. The second step increases the current output by about 20%. This activates the injector quicker, holds it on (poppet valve open) more firmly, and keeps it on just a bit longer. The result is snappier acceleration and a more responsive truck.
After the rebuilding and modifying is done, we run each IDM through a 20 point test on the test bench, and then we run it continuously for 30 minutes at 3000 RPM and 3.0 milliseconds of injector pulse width which is longer and harder than you could ever run a truck in real life. When it passes this test, then it is ready to sell.
We've been doing the high-voltage mod since 2004, and invented the high-current mod in 2008, and haven't seen any negative side effects to either the injectors or the IDM in this time.