International Truck and Engine Corp. unveiled the third pick-up truck in its XT product line last month at the Chicago Auto Show. Called the MXT, the new 5-passenger 4 × 4 has a towing capacity of 8 tons and a payload capacity of 2 tons. A 300-hp. diesel V-8 driven through an Allison 5-speed automatic transmission is standard. The company expects to launch the MXT this summer with a suggested retail price of $69,900-$85,000.