I do not beleive Chevy offers a 4:10 gear with the smaller 5.3 liter.
You can get the 5.3 liter (1500 series) or 6.0 liter with a 3:73 gear (2500 series) or comparable.
When you move up to the HD Series, 2500HD or 3500HD, you have the choice of the 6.0 with the 4:10 gear , the 8.1 liter with the 4:10 gear or the DuraMax Diesel with the 4:10 gear.
For 2005, they may have some changes, but I highly doubt it.
The 5.3 liter was supposedly relcing the 5.7 liter but is no way comparable. You would have to move to the 6.0 liter or the the big boy, 8.1 liter for more hp.
The 5.3 liter would be good to drive around town but not something to make long trips without the tranny screaming. My buddy went from the 5.7 liter to the 5.3 liter back up to the 6.0 liter. He said he'll never go bacl. We've got the 6.0 with the 4:10 gear.