The search function can be your best friend. Lots of good info there. Pay close attention to any stuff from Don_Wow.
There is a shop in Wisconsin that specialize in Olds engines. i talked with them once but have not had any work done yet. I found out about them in a Hemmings.
start here,then read it again. then do a search for DON_WOW http://www.jalopyjournal.com/forum/showthread.php?t=47584&showall=1
There was a series of articles in Custom Rodder a few years ago that dealt with building the 303/324 & the 394 engines. There is a guy in Ohio who advertizers in Hemmings that builds olds motors.I talked to him a year or so ago & seemed like a nice guy who knows what he is doing.