"...this is a numbers matching "nearly" all original 350 car..."
So, I'm wondering exactly which parts are "numbers matching".
Is it the original block that came in the car, or just the correct casting number & block code ?
Since this is the 1st gen site, I assume the car is a 1st gen. I think the heads used on 1st gen 350's were the #17 & #47 on the 2-barrel engines. And the #18 & #48, on the 350HO engines.