Ar-10 kit. - TacFire Ar10 Buffer Tube Kit/Reg End Plate

When I received my kit .and had the time to put it on my Ruger Sfar AR-10 I noticed comparing it to the original one the buffer spring is quite a bit shorter and the treaded part of it with the holes in it was shorter to by I would say about an inch. The crown nut that threads onto that part is much thinner than the original one Ruger puts on it. I made it work but haven't taken it out yet to see if I am going to have a naming problem yet. I feel the after market replacement parts should have been the same length and the nut not made so thin or cheap looking if that's how you want to look at it.