I say it's real....
Keep in mind with your smarty and tall tires a Flex Plate and Input Shaft are Highly recommended.
You might want to change your philosophy on trans a bit.... , stick with a towing Style Valve Body and a VERY EFFICIENT SINGLE Disc Converter. This will make the drop of RPM's to Lock Up less, which will reduce the shock at the moment of lock up relieving stress on input shaft and all other drive line components.
Tall tires equal lower RPMS, line pressure is a function of RPM and if you dial in the tire size with the smarty your ECM to 48RE communication will be altered to shift a little different and I believe earlier. Line pressure is what squeezes through the input shaft to make "Lock Up" happen, if this happens at a lower RPM then the converter has less pressure to accomplish this and chatter or slip is more likely even with big dollar parts, let alone stock converter. The more efficient converter will be supporting lock up and give way better service life to the entire transmission effort, especially if this truck is a daily driver.
Sorry for the book, we were assuming your looking for a trans for the truck in your sig.