ISKY Retainer Question, 507ST and 507STA 7 Deg Locks

Based on what you’re describing, the added installed height of the STA retainer is achieved by raising the position of the retainer on the valve stem, which will have the valve tip lower vs the retainer top……..compared to the ST retainer.

The thing to keep in mind with aftermarket retainers/ locks is……..there isn’t really an industry “standard”.
So a normal installed height retainer from brand A, may not be all that close in installed height to one from brand B or C.