[GMPARTSMAN]

Early 60's Corvair buckets were cheap and plentiful in the mid to late 60's.
In fact, I just missed a pair a couple of weeks ago in a non running '64 'Vair.
They would have looked good in my 55 when it's all finished.

[The Old Guy]

Lamar
If you are indeed planning on acheiving 422 CI from a 322 , you are going to need a VERY DEEP POCKET

[poci1957]

The early GM bucket seats were used in various Pontiacs (which I am more familiar with) and Buick/Olds/Cadillacs roughly from 1958-61, then replaced by a more commonly seen type for 1962-65. These were as seen in Impala SS with the chrome over the backrest. The 1958-61 type had metal backs and are far less common and seem to be big $$$, the later 1962-65 should be much less money and easier availability if that is a concern.