J DADDY, The E-Clips from the Home Depot Store are "EVERBILT" 568 622 3/16" Plain Steel 2-packs. The bar code is 8 87480 09508 1. I have used these on previous Southern Pacific cars.
My order from Home Depot-on-line for 30 packs arrived as "CROWN BILT" CB #43638 Plain 2-packs. The bar code is 0 30699 43638 5. I have not tried these yet, but they look the same as the Everbilt.
Replacement is optional, but I have had two trucks come off these new cars. Because the UP cars are sealed with what appears to be double-sided tape, I am replacing the E-clips as I detail my cars. The silver Lionel E-clips are easy to bend out of "round" shape when applied to the truck post. I made Dean at Lionel Service aware of this fact.
Have fun tinkering with these cars.
I have had to bend truck mount plates up or down to get all four wheels touching the rail. The metal is easily bent and may account for why a "re-bending repair" becomes necessary.
The couplers also need to be bent downward (toward the track) on the Kinematic plate on a car on occasion. As the cars pull, there is a tendency for the coupler to want to raise upward, causing the car to uncouple.
Consider this cars like a guitar that needs to be "tuned up" now and then. It is music to my ears when everything is working well.