The mounting and fulcrum point of the decklid shocks is not ideal and stresses the decklid, hence the need to get the shock pressure correct and different shocks for wing and no wing to avoid warping the decklid.
The recommendation used to be 90 lbs force for a non wing and 100 lbs for a winged car. That said tere are different wing manufacturers and they can weigh different amounts depending on how thick they lay up the fiberglass and the original delta wing is an aluminum sandwich skin.
I recommend the IPSCO relocation kit as it does a much better job of relieving the stress and also forces the decklid away from the roof edge upon opening, which was a particular interference problem for me.