[updated:LAST EDITED ON Apr-11-06 AT 06:53 AM (CST)] _NO_ ~ you want them bled down so you'll be able to feel the ' give '
You can take off the tappet chamber cover on the side of the engine and look at the lifter tops where the push rods sit on them , if the lifter has a snap ring holding the two pieces to-gether , it's hydraulic .
You'll be able to see how much sludge this engine has in it too as this chamber is lubricated my oil returning from the head area .
You can also see by adjusting the valves with the engine warmed up and @ idle , when you turn the valve adjusting screw to _zero_ lash ,
a solid lifter will cause that cylinder to miss where a hydraulic lifter will all the engine to continure idling just fine , little or not audible click .
Many listers here have discovered mixed lifters , both solid and hydraulic , in the same engine so pulling the side cover might be wise
FWIW , I've never worried about it on the 235 in my old '49 shop truck , I just adjust them as solids a couple times a year .
-Nate