"High Performance" VIN ID

I have a second 400 on the stand, dated 1972. I don't know anything about it, but I may take it apart to determine what it is. It has a forged crank, with 906 heads and a 70 Roadrunner Intake on it. It has been in storage for 20+ years. I don't have the time right now to pull the original 400, but if I do I will probably check out the engine on the stand. it could be something Interesting. I will keep everybody posted!