how to tell if 235 is mechanical or hydraulic?

[62lwbc10]

Guys sorry if this is a stupid question but im about to pull my 235 from the 62 C10 and the rebuilder is asking if its hydraulic or mechanical. He tells me rebuilding the mechanical head is more work/problematic than hydraulic. Do you agree to this and how do i tell which type I have? I seem to recall someone in the past telling me it has solid (mechanical) lifters but Im not sure...

THanks,
Mark