USA 1953 high-pressure 235s (in Corvettes) had the two bolt valve cover.
I cannot remember if the 1953 USA 235 Powerglide-equipped car engines were high pressure, but they had the two-bolt valve cover, as did all 1953 216/235 car/truck engines.
Yes, the '53 Powerglide cars were high pressure engines (2-bolt valve cover) and had hydraulic lifters, and all '54 engines were high pressure (4-bolt valve cover). Interesting the Canadian truck engine has a 2-bolt valve cover, which would not have been the case for '54 US engines. The '53 US truck engines (2 bolt valve cover) were all low pressure.
