6lbs isnt that far out of line but 5-5.25 will likely be where you end up at.
Whats the #s on the converter, I am fimilar with hughes stuff. 6500 after the shift is a good spot to be though, big tire is the next option, remember not all cars are the same and if you get the option to barrow some bigger rims and tires from someone you should do it, what works on one will not work on the other. What did you say you were launch rpm was ?
Tigthen that shock up a few clicks also, thats on the soft side.