Need to Mod my 5.3

[ryanmac45]

Just bought a 5.3 TB and really like it. We originally wanted a SS, but decided on the LT with 4wd. My wife and I would really like to make some major performance improvements. I am interested in the HT power programmer, but after alot of reading here, I am thinking about reprograming the pcm. I would also get intake and cat back. would like to get some feedback on some combinations that have been successful. I don't think I understand how something like the Vector Tune is accomplished. Thanks.

[Envoy Fan]

You'll like the 5.3L. Since the 6.0L SS has come out, there are starting to be performance mods that will work on the 5.3L.
The Vector tune tunes both the Engine control module and the transmission control module. I noticed an immediate difference with my Vector tune. I will get the Vector CAI also soon.

[EvilTwin v2]

I picked up my '04 w/ the 5.3 last week. A few days later I installed a K&N CAI. Big improvement in power, fuel economy, and sound. It now sounds great when accelerating, but is still quiet on the highway.

A few days later, I installed a Jet Power Programmer. Hypertech doesn't make one for the 5.3 TB/Envoy. The Jet stepped it up another notch. I can now spin tires on demand (though I'm afraid to with the limited slip rear end...not sure how much abuse it'll take), the tranni shifts more predictably, and I have a ton of flexibility with changing shift points, rev limiter, speed limiter, correct for tire size, etc.

Next I'm thinking about a custom cat back w/ a Flowmaster 70 series muffler.