I just purchased a OEM water pump assy that came fully assembled (awesome!). Not sure if anything has improved over the years or if the impeller should still have the RTV mod done to it? I do have a bunch of the red high-temp RTV I used to seal my water pump on my F250. Can I use it or buy another type? I'm heading to Death Valley in less than 2 weeks. I need a 1 time flawless install that holds coolant!