Hello @Newguy, welcome!
Struts plates are different from YZ plates. There’s also XZ plates too.
Digging through some of the LR3 Build topics created by community members really helped me figure out this stuff when getting started.
Shared my build journey (includes parts I ordered from V1E, metal tube options and a build video) @ Purple-black-rainbow LR3 🤷♂️ , build video @ https://youtu.be/FJ7nYio8oOE
Hope that helps. Look forward to seeing your build journey topic. Cheers!