Jon G and anyone else interested, the information you mentioned on the 1959 235 engine changes can be found on pages 28-29 of this 1959 Chevrolet Truck Engineering Features publication, courtesy of the web site were it resides.
Don't ask me how I remembered where to find these tidbits - LOL!
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)