My dad recently purchased a 65 Belv. with a 440, that is a low 12's street car. This car also has hydr. lifters, if that makes any difference. The original owner suggested running 50w racing oil, but he lived in Oaklahoma, which probably has higher avg temps that we do here in Michigan. Straight 50w seems to heavy when your temps drop to 30/40 degrees F or so? Any suggestions as what to use for oil if your in a state that varies from say 40 degrees F to 90 degress F? Or should I try and speak with the person who built the engine, and see what they suggest? I do have all the spec's and parts used in the engine rebuild. Thanks in advance. Garry Penn 64 Belvedere 2dr Sd, WIP (Work in Progress) 64 Belvedere 2dr Sd, Parts Car 66 Belvedere Wagon (Finally a running car) ---- 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. b7yoMz.