Take the two new springs off....lay them down on the driveway sideways-not like rocking chair rockers, but on their sides. Stack one spring on top of the other. Then line then up one over the other.

Stick a long bolt thru the holes in one end to line it up with the spring under it. Then see how they end up on the other end.

You will see that the holes on the other end don't match up. And if they do, one spring will loop lower than the other in the middle.

Your springs aren't curved exactly alike. They should be.

It really is that simple.

But wait!....Even if the assembled springs seem to be curved the same, the spring assembly with the open gap will offer less resistance when loaded by the weight of the truck...So that side will be lower when the truck is squating on it.

You know deep in your heart it ain't right, so send them back.