As I run a auto parts store, I feel qualified to answer this question. Regarding a diesel engine, the only way to effectively introduce Seafoam is half a can into the fuel tank, and half a can into the crankcase. Used in the crankcase ESPECIALLY produces a good cleaning on the piston rings. Half a can in the fuel does a ok job of cleaning/lubing an injection pump and/or the injectors.
A better solution, however, might be using a conditioner from Power Service. Part numbers 1025, and 1080. This is the best diesel fuel conditioner/cleaner I have EVER seen or used. It is specifically designed for diesel engines. It also contains "Cetane Boost", an additive designed to boost to combusibility of todays diesel/biodiesel fuels.
While Seafoam is a great product, I strongly feel you would be better served by visiting your local parts store and buying part number 1025 or 1080 from Power Service. It will work better than Seafoam part number SF-16 in your 6.2....please trust me