Im installing new shocks and struts on my 86 GLH Turbo and got a couple questions.

Fronts
Do the factory springs come with a tag and a three letter code on them? Mine have a paper tag with XHD printed on them. Also, the little tang protruding from the outer circumference of the upper strut mount....it looks like that is installed 180 away in relation to the lower knuckle mounting tabs according to the FSM I have. Is this right? Im confused here because this seems opposite of the notch on the upper strut mount on the K-based cars which lines up directly with the lower tabs that attach the knuckle.

Rears
It appears one of my rear springs was either cut or broke at some point. It sits (freestanding) about an inch shorter than the other and is one coil lesser than the other. Would it be possible to use Shelby Charger rear springs on the GLH? Those are the only other springs I have on hand, aside from a set of BC coil overs that I didnt really want to use for this project. Also are the rear upper spring seats no longer available for the L-body? I cant find them anywhere. I can find the isolators, but not the metal spring seat that goes under the mount cup.