Towing up the mountains

I tow all over with my 3/4 ton gasser. Some pretty good grades here in Washington, Oregon and Idaho. I just let it sign at 4000 RPM. The 6.0 doesn't make peak HP and torque until 4400 rpm. For the limited amount of time you are that high in the RPMS you are not hurting anything. That is what they were designed to do. It is rare I have to put the 6.0's pedal on the floor, but combined I am at about 14,000lbs. I can't even begin to count the times I ran my old 89 TBI BBC with the pedal on the floor 4000 rpms to get over the Continental Divide, up Vantage Wa, 4th of July pass and Look out Pass. I put almost 200,000 miles on that thing.