I've been doing a lot of research on gears in the past, the only major complaint was the gear was noisy and can be difficult to set up the tooth contact pattern.
I installed a set of Nitro 4.30 gears in my 2004 LLY and they are doing great, no issues at all. I can tell you the crush sleeve they supply with their install kit is one heck of a MF to get crushed to the proper height, even with a big ole impact wrench. Nice and quiet going down the road.