so thy just sit in there ?

Yes. One small end of the coil seats perfectly around the lower bumpstop and self centers on it leaving it resting on both U-bolts. The other small end of the coil I cut about 4 inches off of so it would sit flush along the side of the strike plate. I will be adding some bolts with fender washers to the strike plate to ensure the coil does not pop out of the top. Then, if it gets pulled off of the bottom, the bumpstop will act as a self centering device to line it back up so it will rest  back where it was. Make sense?