Ticking valvetrain noise from fresh engine

It sounds like a preload problem I have heard of other magnum roller to flat tappet conversions that were noisy lifter and it came down to one of two things, preload as previously mentioned and or/the "correct lifter". The mopar and amc lifter are sold under the same part number but there is a difference between and the amc lifter is the one that worked best, I have also read that the comp cams kit to do the conversion has proven troublesome.