Post the engine serial number and people can tell you what the engine originally had for lifters (this code is pressed into the block, just to the rear of where the distributor enters the block).

Prior to 1956, only 235 engines installed in cars with Powerglide transmissions had hydraulic lifters.

From 1956 onwards, all passenger car 235s had hydraulic lifters.

No truck 235s had hydraulic lifers, except perhaps late 235s in trucks with Powerglide transmissions (no one has yet found GM documentation to confirm/deny this).