We had a discussion here a while ago on break-in oil. The most recent Mopar Enthusiast magazine has an article on oil in general. The article says to always use oil with zinc for our old cars, not just to break in the engine. Some highlights in the article: It says that in the future Shell Rotella oil, and other diesel oils, will be no longer adding zinc. A new API "SM" standard will force that. Mopar Performance is rumored to be bringing out a zinc additive to make current oils compatible with older engines. Crane and other cam manufacturers sell an engine break in additive that you can add at each oil change and use regular oil. For now, look for API ratings of CF, CF-2, CF-4, CG-4, CH-4, CI-4, or CJ-4 on the oil bottle. CF-4 has a lower zinc content than other C ratings. Racing oil and some motorcycle oil (Harley Davidson Syn3) have zinc, as does Royal Purple synthetic with an SL rating. Gary H. ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.