Any links to make this a wonderful task. My engine made it to 502,000 miles before it quit pumping enough oil. Trucks in great shape. Even still will run.But not really drive able.

 

Damn! I can't offer any advice, but I would like to know if you did anything special to get over 500K out of that engine? Hell, Try replacing just the oil pump and see how many more you can get.
Seriously though, good luck. Lots of folks on here recommend Jasper engines. Some people take the fenders off, some have taken the cab off.