I thought my rear main seal on my M1008 was causing my leak but I've now found I have oil leaks at the rear of both heads. I may purchase the UV dye to make sure, but my questions are: 1. Does this sound like more than just a head gasket change? 2. If I have the heads removed what else should I do while they are out? (60,000miles) 3. Is the only advantage of 6.5 heads on a NA 6.2 better cooling? Or would it be worth it If I plan to add a turbo in the future to make a swap now? My truck runs fine otherwise, just want to get rid of the little puddles. Thanks in Advance.