What load range is the LT? If it is a C or D range then I would put them on. If they are an E range, I would look at a different tire as E is way too much for our trucks (10 ply and HEAVY). If you are doing any towing at all with the truck I would avoid a P series tire. If you are not then a P series tire would be adequate. You will also get better tread wear out of an LT tire over a P series tire on our trucks. My stock P rated Rugged Fails had less then 17k miles on them when I had to replace them due to tread wear!