James and his team did an excellent job rebuilding the entire upper half of my 6.7 Cummins. Every seal and gasket has been replaced, head bolts were replaced with studs and the head is freshly inspected and comes back like new from the machine shop. All for an absolute fair price. James also took his time to explain and show me a lot about tuning the engine just right so it runs perfectly smooth while making real good power. Top notch service and work for sure. I would HIGHLY recommend Weavers Diesel Performance to everybody.