Welcome to the dark side! Smallblocks are a lot of fun. A set of less restrictive exhaust pipes will make a noticeable difference in that low rpm flat spot. You have quite a choice now, Guzzitech makes some, Staintune, Mistral, Agostini, Zard, (I think), etc....
There are a growing number of good internet resources for the small block Guzzi's as well. This forum of course, and the smallblock group on Yahoo, http://autos.groups.yahoo.com/group/MG_750/
. Lots of good info there.
Wildguzzi is fun too.
Oh yeah, this thread is worthless without pics!!! LOL