The desired AFR question came up recently. I've heard that a good WOT desired AFR for the 3800 s/c is 11.6:1. Of cousre this varies based on mods, I guess. Apparently the V8 guys (Mustang, Camaro, TA, Vette) tuners say that 12.5:1 is a good spot. This can be found at places like HPTuners.com.
If what I've read is correct, is there a reason for the difference? I don't have a WB, but am always curious as to why things are the way they are.