AFR for a N/A vehicle?

[jesse096]

I know a boosted car needs to be tuned differently than an N/A car. I just hooked up my Wideband yesterday, and took a few readings.

At idle: 14.3-14.7
On the gas below 3K RPM: 14.7
On the gas at anything above 3K RPM: 12.4
Right before it shifts at 5K RPM: 12.0

Are these normal? And I'm only reading one bank right now, I had a plan to cut out my cats and weld one in further down down past the Y pipe, but no muffler shop will do it for me. Can I get this thing tuned? Or is it pretty much good where it's at? I wanted to just get a nice street tune to get a little more power.

BTW It's a 2002 Silverado with a 4.3L V6.

-Jesse