Here's a link to download the FRPP 2008 catalog in case you haven't seen it yet. I read on the Dubia Mustang board that FR now has 3.90s - they don't. But at the begining of the catalog is alot of good info on the state of Ford Racing. Imbedded in the rest of the catalog are tips on parts installation.
So who's the most respected vendor of 3.90s? Richmond? I hear 3.90s are noisy by nature, is that possible?

http://www.fordracingparts.com/download/catalogs.asp