I had a friend that told me he had a 300HP sbc in his barn, belonged to his Dad and he had it in a 70 chev pick up. It had been in the barn for years and his Dad had since passed. He brought it out and I stuck it on the eng stand, run the numbers and the short block was a 69 to 73 307, the heads were built on April 15, 1966, they are the 462 castings. The motor turned over with no tight spots and the carb, 4 bbl carter wasn't even froze up. He stopped by today and I told him it was a 307, he said his Dad had the 307, had it gone through by a old drag racer and made it into a 327. He put the double hump heads on it at the same time along with the 4 BBL carb and intake. Year or so later he wrecked the truck, pulled the motor and sold the truck. I can't help but think that it must have been a really good block to bore it that much. I'm going to tear it down to the short block for the heck of it, may sell some of it or use it on a furture project. I think the carb and intake are 1966 also, my memory isn't that great, I'll check the numbers on it sometime. A couple of pics of it.