Seafoam or Berryman's? I'm thinking I might need to clean out the combustion chamber/valve train on the '60.....do these products actually work? Any damage to seals/gaskets/etc...? Negatives? Positives?
Always have been hesitant to put any aftermarket additives into the system so those with firsthand experience please pipe up before I go and do something I might later regret....
Thanks,
-dogboy- '87 FJ60