i am looking for a good mod to put on my 04 silverado 5.3 with handheld programer and a true flow cold air flowmaster.what should i do next thats good and dont cost a arm and a leg and not to hard to install .
i will try anything

 

Sell the programmer and get a custom tune from a sponsor. You'll notice a big difference.

 

^^^I agree

 

on the custom tune.

then after that, get some longtube headers and off-road y-pipe and get retuned for them

 

+2 for the tune and longtubes

 

GEARS, if you have 3.23 or 3.42.....

 

Tune.

 

If you plan on taking off the cats, which will def. help, I would wait til after that to get the tune. But with no cats and a good tune I would say probably another 20+ hp, just guessing but the cats are good for 8-10hp. Also, it's a little bit more money but a dyno tune would really be the way to go. Around here a street tune is common because it is about $150 cheaper, but I'd spend the extra money to have it done right.