Greetings,
 building a 318 for my brother in his 01' 1500.  Wondering if anyone can give me a basic rundown of the late model 318s.  What years did the big changes happen?  I.E. cylinder heads,roller cams,etc.  What makes a magnum, a magnum?  What are the areas of most concern in a performance build on this guy?  What are the least?  Any other kind of good general info on this engine would be helpful, and truly appreciated.  Knowledge is power.  Thanks in advance,

Aaron