"Hydraulic lifters came with the full pressure engines, circa 1954. All 235's after that had hyd."
That might be correct for passenger car 235s but it is not correct for truck 235s. All USA truck 235 engines had mechanical lifters.
As stated above, hydraulic lifers were also available on some low-pressure pre-54 235s.
WHO ME,
Yes you will have to adjust valves with either kinds of lifters (different procedures and intervals for each type of lifters).
In the good old day, I know people who adjusted their mechanical lifters every 3,000 miles or twice a year - I will check the Owner's Manual tonight.
Tim
