9B428422 1969 440HP2 in W300

So I just picked up the 76 power wagon, and I knew it had a 440 in it, but started looking at it closer and it is a 69 440 HP2 engine. numbers on side of engine are 9B428422....ideas to what it might have came from, and if someone might be looking for it before I consider building it for a 74 ram charger project. Thanks in advance as always
Dynotune

it would've been a Charger R/T - XS29L9B428466 does it still exist??