AFAIK,
I have looked in all of my Ford and Shelby books and talked to a friend who has one of the PI 428s. The only difference he could find between it and the Thunderbird version was it had a step up or so in the camshaft. He said his block numbers matched the numbers on a friends 1966 thunderbird. I know one version was rated at about 345 horse and I think that was the one they called the police engine. I am sure there is more and someone in the club will be able to tell you exactly what to look for. I know that my 1969 Torino NASCAR Cobra has the 428SJC and everything in it is completely different from the other 428s including the 428 CJ. Wish I could help more but those numbers get confusing espceially when the books don't always agree. The date codes are on both the block and inside the valve covers on the heads so you could look at them and that will get you into the years range you want.
Ron61
Ron Widener