Grand Prix question

[olredalert]

------As long as Pontiac questions are being asked,maybe I can pose one?
------I have a 64 Grand Prix optioned with the 421HO/tri-power,and four speed trans.I know the combination is a rare one but am wanting to find out how rare.This car is proven by 2 build sheets and PHS documents.There were around 3300 421HO/tri-power/four-speeds put in big body 64 Pontiacs,but by far the majority were installed in Catalinas,2+2s,and Venturas.Ive actually asked Jim M this question and he said the PHS services have no way of narrowing down on the usage.Ive only ever come up with 5 or 6 of these GPs and a couple of them are not documented.What do the Pontiac pundits think?..........Bill S