red's right about the 637, I was off on the size. The 235 did see some use in '63, perhaps using leftover engine stock. I've never seen one myself, though. The 283 was intorduced in trucks in '57, but only on 1 1/2 ton and larger,2 ton and larger trucks, 1/2-1 1/2 tons used the 2 bbl 265, same as the base engine in the passenger car. After the introduction of the 348, the 322 Buick engine (called the Loadmaster V8 in trucks) was limited to the School Bus chassis. Pre-'58, it was found mainly in trucks with the tandem equipment and the Powermatic trans.
