I have never seen an MDS lifter in a 5.7 go bad, only the NON mds lifter... since the 6.4 and 5.7 use the same lifters I would say it is possible but very unlikely as the non mds lifters usually go bad first. As for your question I have torn a couple engines apart after lifter failure and there is never any bearing damage so now I just put a cam in, dump a couple gallons of diesel fuel thru it with the oil drain plug removed to try and clean out the pan a little and send em.