Originally Posted by LarryBible

ABSOLUTELY! This is GREAT oil for earlier gas engines with already broken in flat tappet cams. It has the ZDDP additive in enough quantity to keep it healthy. Additionally the added detergents for soot dispersal help keep a gas engine squeaky clean. In fact for an old engine such as the B Mopar you talk about, I consider it mandatory.

Do not use such a heavy weight in later cars with roller cam followers. Most modern cars use something on the order of 5W20 and work best on it.