How can I tell what kind of lifter (mechanical or hydraulic) my 396 has?

I bought my 70 Camaro with the 396 in it, and I have no idea how they built it, what cam, etc. I need to adjust my valves, but I need to know what kind of lifters I have, hopefully without taking the intake manifold out. I can see the tops of them through oil holes in the head, but according to Crane cams webpage both lifter types look the same on the outside.

What can I do to tell which ones I have?

Thanks,

GP

 

You should be able to take a pushrod an push down on the lifter. If it is a hydraulic cam you will feel the pushrod sink a little.With a soild lifter you will get no movement.

 

make sure you do that test with the rocker loose!
If you try pushing down on the pushrod when the lifter is holding the valve open, it won't move any because the valve spring pressure has already pushed everything down!

 

Thanks guys. They are hydraulic for sure.

GP