66 cuda trunk hold open rod

I have a pair of them. Shoot me a pm if you still need one

Pair? There is only one.

66 uses a spring-loaded piece that just snaps into palce as I recall.

Correct, the mid 65 and 66's take the spring loaded prop that has a hook at each end, the 64 and early 65's take the ratchet type.

The deck lids are also different, but are interchangeable with some slight mods.