They should be hydraulic, IIRC only the early 6s had solid lifters, they also came with adjustable rockers. Later on they went to non adjustable ones.
it may be froze up or stuck, try a strong magnet , if it is really crudded up spray a little pb blaster around it and let it sit overnight, that is why i use a magnet if its an old engine and has been sitting for a while ,its hard to tell what may be stuck when you start to pull it apart
Ok, finally removed the lifters, wd40 help, so now I'm going to start installing everything back . Thanks alot for all your help