Yeah, I know. There seem to be very few people who have any kind of a clue about the older Buick engines. I tried to educate the poster on what he probably had but I guess he didn't want to hear it. https://rockford.craigslist.org/pts/d/rockford-buick-340-nailhead-motor/6933828664.html
It's a shame. Guy has the only original 340 Nailhead. 1 of 1, and only wants $400 for it. He's gonna get ripped off for sure...
OK, those are 64 300 heads and intake (219 casting). The heads will bolt up but the manifold wont and the ports wont align with a 340 manifold. Actually, the heads and intake are worth what he's asking.
Some of us call the small blocks 'pinheads'. In this case, the term could be applied to the seller as well!