Mike, thank you for the wealth of information! Very helpful. I like the idea of converting and willing to spend the money for something worthwhile. I'm going to PM you about the 9.25 axle.

I've sealed up the engine and trans nicely and have the truck running great, so I have put some miles on it to identify leaks. I'm cleaning years of [censored] off the transfer case and new wetness is appearing, but still hard to pinpoint exactly where it's coming from. I'm going to have to pressure wash I guess. I've been using a scraper to remove what was coming off engine when it was leaking out a rear freeze plug, oil and trans fluid so that every bit of dirt stuck. There was almost an inch of dirt stuck to transfer case, and in every little nook and cranny. Yep, FSM states 10W-30 engine oil for transfer case.