I replaced the rad and installed a 180 thermostat at 200k and my operating temps are 188 to 193. 197 is the max when idling for extended periods. I did a 2" lift with 32" tires and hooked up a center diff lock linkage. I do some wheeling and have driven this vehicle to Florida and back 3 times (the most recent was at 430k). I have only had to tow it twice in the 10 years that I have owned it - once when the belt idler pulley grenaded ( I should not have ignored the tell-tale chirping) and once for a bad CPS ( I knew it was well beyond it's life expectancy and had a new one in the garage that I hadn't gotten around to installing). From my experience, with proper maintenance, these vehicles are reliable. Having said that, my last vehicle (a Chevy) had 440k on the clock and was still driving when I got rid of it.

 

Several years ago I got a 5 gallon pail of Redline 75w-90 at Amazon for like $65 delivered. I think they had the pricing wrong, but that's what I've got in my boxes. Has been working great. I'm not sure why so many on here want to use the 140w stuff.

 

 

Redline 75w90 works great for me.