These are good reads with a lot of info, maybe a little more than what you were looking for but a lot of good info.

http://www.moparts.org/Tech/Archive/bb/25.html
http://www.moparts.org/Tech/Archive/bb/26.html

'75 Plymouth Duster
Phase I 451 906/590/2-660 10.75/126
Phase II 451 Stage VI/590/1050 9.82/135
Phase III 383 906/Victor-Pump gas 11.30/119

"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,"