That stamping is pretty funky...but I will trust the experts that it is real...The fact that the motor had all the original parts kind of confirmed it prior to seeing the stampings...and I did see the trans with no less than 7 vin stampings...
Cool motor !!!...dont deck it...and try to find the car first before doing anything....!!! Then, if all else fails...you can donate it to me for my car,ok !!! haha
Time to find a 67 Z body to build a car around your motor... !!