To check valve stem to rocker arm clearance (with hydraulic lifters), is it acceptable to just push the rocker arm into the pushrod (so as to bottom the hydraulic lifter) and then measure the clearance between the rocker arm and valve stem with a dial indicator or feeler gauge? I've been told that this is ok, but all the books say that you need a special lifter leakdown tool.

 

I forgot to mention that my engine has non-adjustable rocker arms.

 

What info are you trying to get here? I don't understand the question.... Are you looking for checking valve lash on a non adjustable rocker? If that is the case just go 1/4 turn from zero lash to 18ftlbs and it's a done deal... Thats if you have the cam lobe in the right spot.