Freebeard, Have you seen this thread?
http://ecomodder.com/forum/showthrea...etle-8412.html It is about a newer version but I think you share some of the same aerodynamic challenges (except engine cooling). He used to have his own website with more info at maxmpg something or other. I did a quick google search and didn't find it this time. I like the idea of experimenting with a boattail but I wonder how much benefit you will see down in that dirty air. I guess there is only one way to find out.