It is my understanding the difference is in the heads on a "Magnum" block...The magnum had a larger exhaust valve (1.74 I think!) and a better flowing pocket. This began in the 915 head casting in 1967 and continued until the 906 was introduced in 1968...the 906 had the standard 2.08 intake and the 1.74 exhaust was made standard. The combustion chamber was now an open 88 cc design. This was standard in ALL RB/B despite the misconception that it was only in "Magnum" applications. This was due to advertiseing claims of the day. The only difference was the Magnum's had stiffer valve springs stock. The 346 head was introd. in 1971 on all B/RB engines. This was a smog head...and not very performance oriented. It was raced in NASCAR with many modifications in these years. Hope this helps. Bob Fortson --- ledman_70@xxxxxxxxxxx wrote: > Your free subscription is supported by today's > sponsor: > ------------------------------------------------------------------- > Take our Nationwide Ice Cream Survey today! Receive > a FREE* $100 > Restaurant Gift Card of your choice or $100 worth of > Ben & > Jerry?s® or Häagen-Dazs® ice cream for > participating! > caad3P6bQmH9Ma/Ice > Cream Research Survey > ------------------------------------------------------------------- > > Thanks for the info everyone. So, there is no real > difference between a > 440 Magnum block and a 6-pack block? Are they marked > the same? > Jeff > Joeydahook9@xxxxxxx wrote: > > > > > > Jeff - the F means 1970 and the numbers 2 13 and 1 > 9 are the month and > > day > > of the engine build date. Mopar stamped engines > with HP2. I cannot > > find a > > designator for a six pack engine. Joe > > > > [Non-text portions of this message have been > removed] > > > > > > Jeff Adams > 64 Polara > > Your free subscription is supported by today's > sponsor: > ------------------------------------------------------------------- > Need a new Cell Phone? A BlackBerry 7250 could be > yours free! Find > out how! > caad32RbQmH9Mf/Amazing > phone > ------------------------------------------------------------------- > > ---- > 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. > > > ______________________________________________________ Yahoo! for Good Donate to the Hurricane Katrina relief effort. http://store.yahoo.com/redcross-donate3/