well i currently got 42" TSL's on now but they are very worn and have lots of dry rot. i decided im going to go with a 39.5 Swamper but im not sure which one. originally i was going to get the TSL because it has deeper tread depth which would help because this truck sees lots of road, with offroad as often as possible. i did a poll a while back and i believe the verdict was tsl over irok for a dd. but now they have a 39.5" Irok radial. im not sure how the tread depth compares, but would that last longer than a bias TSL even if the tsl has more tread depth?