a friend of mine went to a 351 windsor non roller block. He needs a cam and lifters for it, but I have never messed with a 351 and I don't believe he has either, so I'm trying to help him out

visual inspection, how do I tell a flat tappet from a hydraulic roller from a solid from a solid roller cam?

does only the hydraulic roller need link bar lifters to use, if not, how do I decide it can use mechanical solid lifters?

appreciate all help in advance,
Rick