Good Reason for 4.10's
Cummins Cowboy,
The 4. 10's give a GCVWR of 21,500 lbs and a "trailer tow rating" of 14,700 lbs. The same truck with 3. 54's has a GCVWR of 20,000 lbs and a "trailer tow rating" of 13,200 lbs. Our trailer has a GVWR of 13,500 lbs - too heavy for the 3. 54's rating.
With more attention being paid to combined weights of large 5ver rigs and the legal implications of being involved in an accident (regardless of who is at fault) or even being stopped for weight checks in an overloaded rig, we're getting the 4. 10's strictly to be legal anywhere in the U. S. or Canada when pulling our 5ver.
I've been in contact with U. S. Gear - they will soon have a 20% OD available for the 4x2 NV5600. I plan on installing one for use when not towing as well as for "gear splitting" while towing.
Rob, with the stock retarded injection timing of the 24v ISB, I'm not surprised that a stock ETH might run excessively high EGT's while towing. I would think that, by advancing the injection timing back to where God and Clessie intended for it to be before the EPA got involved as well as by increasing air rates through the use of the boost elbow and module, the Edge EZ could be helpful in reducing EGT's. Of course, the higher fueling rates would work to increase EGT's at the same time, so maybe the net result is a wash.
Rusty