Wow - that would be an impressive amount of truck for 4500.
The Texas truck market is probably way different from other areas where theyre less prevalent.
Id trust a 5.2/5.9 Dakota way further than a slightly newer 4.6/5.4 Ford that's going to start having cam phaser issues on 'low' oil pressure that the 5.9 would run another 150k on. My. 02.
