If either the cam or lifters are machined incorrectly, treating them isn't going to make any difference. They'll still likely fail. Get the parts examined and/or touched up by someone who knows what they are looking for if you aren't capable. Checking lobe taper on a cam is fairly straightforward but finding an improperly ground lifter may not show as easily. Then, if you want the benefits of the cryo treatment, have the known good components treated.