apbmalibu.

If you are referring to an original truck engine, all truck 216/235/261 engines had mechanical (solid) lifters.

Many (maybe all?) automobile 235 and all Canadian Pontiac 261 engines had hydraulic lifters.

Some later truck 235 and 261 blocks might have been able to use either mechanical and solid lifters but they still came from the factory with mechanical lifters.

Tim