I can possibly tell you as much about EPD and many of their diffrent head designs over the years than most can.
I am and have been a big EPD (Larry OLsen) fan since my first set of old Pro Stock Heads back in the early 1980 'and before the BB Spread Port stuff.
.I lost contact with Larry last year.
I am fairly familiar with his many different designs for Pro Stock BB Chevy/Olds/Pontiac stuff, his intakes, His steel shaft rockers,
I am not familiar with his many diffrent head mods for each individual engine.
HIS CYLINDER HEAD NUMBERING SYSTEM WAS ONLY IN SEQUENCE. So if you have a head for example that is a larger serial EPD # that only means it was done later in years than one with a lessor number.
The EB Series Castings were all cast by Brodix to be under exclusive contract. Not sure how that contract would stand now that Larry is out of business. The EB SEries designated headfs were larger number for the larler engines, most popular was the EB 650 series with very few engines capable of thinking about the EB 700. The EB 600 and below were for the BB Style engines below 600 inches.
One of my better customers just got a set of the newer EB 650 EPD heads, in a package deal that is newly freshened built and dyno tested that I am very anxious to get inside. and see how much more power I can get than the former owner's builder.
Man I just gotta get back to work after we shake this cancer.
Ed