I spoke with Carl last night. Very nice guy by the way.
He confirmed the 20%-30% weakness in running coast vs drive. said he had seen numbers ranging from 18% to 28%.
Which makes the low pinion K4 setup stronger than swapping to a stock high pinion D44. Add in a load bolt and Bob's your uncle.
He made an interesting point about coast vs drive, in that when backing out of a deep hole your stuck in, you're going to be switching from drive to coast or coast to drive. He said the reason load bolts were put on big rigs was due to strain of reversing heavy loads.
So... bigger gears or not, load bolts are a great idea.
Hinmaton