Thanks Airy Cat. That's what we need to compile a more complete list. I have added the numbers you have found. I would like to set up something where Buick owners can add info they know of.
Having trouble accessing the nailhead numbers list. No authorization?
Saw an engine at an upcoming sale, and could read 11663491 on one of the heads. The pic is kinda fuzzy, so not sure about the first 6.
All the casting numbers I have that are reasonably identified are listed.
You can tell which motor the intake will fit by measuring across the stud holes. The measurements are partway down this page: