http://www.chevelles.com/shop/ss_ident.html
While a good overall reference page there are some errors. For example under 1971 it states, "For 1971, there were two SS packages. One was the SS-454, and the other was simply the "SS" (available with either the 402, 350-4, or 350-2 engine). The unusual "Malibu 400" package was also available on the non-SS Chevelle and El Camino. It utilized the LS3 402 motor."
There was only ONE SS package available in 71 (and 72), that being RPO Z15. It is true that only when the 454 engine was ordered was the engine size added to the badging.
No such thing as a "Malibu 400" package any more than there was a "Malibu 350" package. In both cases the engine size was added to the Malibu script on the fender but there was nothing "special" about ordering the LS3 over the L48 or L65 as far as any equipment is concerned. Not sure about 71 & 72 but in 1970 the LS3 could be ordered in any series and any body style.
As for the hood pins, I've never seen a 1970 SS396 or SS454 with hood pins UNLESS it was ordered with the ZL2 hood. Hood pins were part of the ZL2 hood package just like hood & deck stripes and not part of either SS option. In 71 & 72 hood pins were part of the (single) SS option and therefore should be on every 71 or 72 SS regardless of engine or hood.