6.0L Powerstroke STC Fitting Upgrade. Over the years it has been found that this part has a very high failure rate. Minor leaks could cause hard starting, especially when hot, while catastrophic failure in which the fitting blows apart will cause the engine to die and not re-start.
This one item changed my VT 275 from not starting to running with better injection pressure than I've had in years. Every 6.0 owner should have one of these installed. So many high pressure oil pumps for these engines are installed needlessly. This one item could transfer your pressure from the pump to the injection rails successfully and at a fraction of the cost.