The 3:42 is absolutely perfect for the g56. Much different animal than the nv trannies. The g56 w/ 3:73 is at roughly 2200rpm at 70 mph, same as an older truck w/ 4:10's. The 3:42 is like havin a 3:73 and the auto, the 4:10 isn't even an option with the g56.
Sorry, my mistake.
courierdog, what kind of mileage are you getting with the 342's?