Thanks for all the great ideas, my reason for asking is because a good friend of mine had a set of 5.13 for a Dana laying around and I wanted to try them, went ahead and put them in today and I'm gonna try them this Sat, I'll get back on and let you know what happens. I have another buddy with a 3400lb car that runs close to the same set up with a 5.38 gear and he runs 6.0's so we'll see.
Again thanks for the help