If you go to the Mopar Muscle Magazine website and go into the tech archives there is a 3 part article that gives a pretty good history of big block heads. You can follow the link I posted earlier to get to Pt. I. Sean B wrote: > > Thanks for the help on these heads. I'm still trying to lock down more > info, like when they were produced. > > Rick E. at Mopar Action once wrote that big block Mopar heads mid-1972 > on up have hardened seats. Does that mean all 346 and beyond heads are > this way? > > Sean Paul L. '63 Sport Fury 440/727 http://www.1962to1965mopar.ornocar.org/ml-lennemann63.html ---- 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.