Daryl, As Matt indicated, Atlas trucks come with an insert that you can use to convert MTH cars. Once you remove the 4 screws on the bottom of the car to separate the underframe from the car body, you can then remove the MTH trucks. Then pop in the black inserts (plug) and screw in the trucks that's all there is to it. Often you need to use a screwdriver to hold the plug in place while tightening down screw that holds the trucks. Use the Atlas provided screws from the same package the inserts came in.
I'm waiting on Kadee's for this car, which I use #740's but looks like it will be fairly easy just drill and tap for the screw size of your choice.. Mine is 2-56 for couplers, others like 1-72. If anything might require minimal shim to keep the Kadee gearbox level.
Often MTH updates their tooling to include screw pockets for Kadee's. I don't have many of these 2-Bay ACF Covered Hoppers from MTH, so I'm not sure if any of the newer runs of these cars include any of these enhancements? Perhaps others know?
