It’s been called the wide-block, big-block, semi-hemi, baby hemi, poly 318, old-style 318, and the list of nicknames goes on. The 318 cubic-inch (5.2 liter) V8 engine that was under the hood of the Plymouth in 1959 was technically referred to by Chrysler as the A-series engine, or polyspheric-head engine. At least one early Mopar enthusiast was considerate enough to put together a web site describing the most technical aspects of this engine along with its history in various Chrysler products. Click the link and read on!
Yeah, that’s a cool site – I wish he would keep it updated.
Here’s a link to Victory Librarie’s Poly Performance book, often for sale on eBay under literature:
http://victorylibrary.com/mopar/poly-book.htm
He also provides a board for us “A”-blockers:
http://victorylibrary.com/wwwboard/index4.html
Good stuff! Maybe when I get my act together, I’ll get these links on the Links page… (sigh). The road to h*ll is paved with good intentions… 
Dan