The lifters in pics came from a 440 I purchased a while back. They look like hydraulic and have a hole in the groove on the side but don't compress when pushed on the top. The top looks like a hydraulic also. I believe that I have seen something on this topic before but don't recall info.

Any help appreciated

Thanks MoParts

2nd lifter pic

3rd pic lifter top

Those are hyd. lifters. They're not compressing because they are full of oil. If you want them to compress take them apart and drain the oil.

If you are thinking about reusing them I hope you kept them in order as you pulled them. I wouldn't use them if you mixed them up or are installing a new cam.

Thanks for the input people. Yes indeed the lifters were kept in order.

Thanks MoParts!