No spacer donuts, no difference in springs, etc. this has been beat to death on the 392 owners group on FB which the product lead is always weighing in and providing accurate details. They have same lift heightHopefully someone has the official service manual for both the standard 392 and the 392 XR. I've heard all kinds of things about the XR package, including the addition of the 1.5" lift (I think it's the simple spacer donuts on the springs) on top of the 392's standard suspension. I guess I'll know for sure when I take a look at mine when it comes in.