Hi Guys- need some help. I have a 1968 GTO that was built in Fremont. When I purchased the car, the original motor was included in the deal. 9790071 YS. I have that motor on a stand preparing for rebuild. The car came with a running motor in it. Here’s the catch: it’s a block code 9799914 YD. I have the Pontiac casting # book and can’t find that motor. It’s currently got the #16 heads and 4bbl intake from the original motor on it. Is this block a ghost? I’m pretty sure it’s a 70 casting.