I'll probably be called a liar on this but I pulled a trailer Alaska to Seattle Washington down the Alcan. I pulled a 25-foot V noses enclosed trailer with 8226 lbs (scaled in Canada in Whitehorse) with a m1009 spring helpers in the back a high Performance Radiator from Silla, high flow water pump from Peninsular Diesel. A transmission cooler all new synthetic fluids in everything. A 160 thermostat, had to stop and drill two 3/8 holes in the stat. Installed temp guage. Had to watch temp steep grades some at 5mph in low range 1st gear and stop to cool down. Could not drive over 55 on Flat ground unless I wanted to die. Going down hill was equally a challenge I also installed new injectors and a Fluid Damper.Long trip. Six months later drove to Texas, mapped out a route with fewest hills as possible. Took 11 days. I drove that M1009 for 3 more years no blow by or issues. Then some ass wipe hit me totalled out my Blazer killed another guy and obliterated his Ford Escape, no insurance. My truck was 90% completely restored.Three years later I found a 1008 now that I am restoring A/C 9 yards be done soon. Love the 6.2 treat it right last a good while. Dream of an Optimiser Engine, oh I did get a deal on a gear vendor so I don't push therods through the block. Semper Fi