Are lifted struts same length as stock?

I just purchased a new 5100/2883 strut to swap out my stock set and when I put them side by side, they are both 20.5" long top plate to bottom of strut. I know the original owner and he said he only replaced the front shocks once with a OEM and no changes to the suspension. Does all this make sense or should the new lifted strut be taller?

 

Never heard of 5110 or 3883, but my 6112's were the same length as stock, and use spring preload to increase lift.

oh, is the 3883 the old man emu springs?

 

I just edited my post. Meant to say Bilstein 5100 with OME 2883 springs. So that's normal then. Thanks!

 

So if both struts seem to have the same length spring and the bottom cups seems to be at the same height, would mine have a different preload then. My 5110s are one the lowest perch.