if you're looking at a Le Sabre, that should have a 364ci Nailhead in it ... which is a bit of an odd duck. there are no other Nailheads with the 364 deck height.
any other Buick model from 1959 should be equipped with a 401ci Nail, which shares most parts ( except for the pistons ) with the 425ci.
The way to crush the bourgeoisie is to grind them between the millstones of taxation and inflation.
Government schooling is about "the perfect organization of the hive."
H.H. Goddard, Human Efficiency (1920)