Just picked up a 2002 Sierra and wondering where to start out for power upgrades. Brand new injectors and high pressure pump the part numbers respectively being 97729095 for the injectors and 0986437303 for the pump. Idk what the specs are on the its just whats listed on the doctors bill I got from him after its last visit to a mechanic. The truck has 190000 on the odometer as well. The injectors and pump were replaced approximately 6 months ago. Just looking for 450-475 hp at the crank nothing crazy. Also still needs to be able to tow full load as it is still a work truck.