I have a 1984 chevy pickup with a 12" lift and 35" tires. I just blew the 454 that was in the truck and I am considering swapping it for a 6.2L diesel. I need to know what this truck is going to need. I have a TH400 that I want to keep. How much stuff am I going to have to change. The diffs have 411's in them, Is that too low? And how about the cooling?