I have a 04 silverado with the 5.3 flex fuel motor. I'm sure a hundred people have asked this question, but I'm going to ask again with hopes of response. I'm looking for some good mods. to do to the motor, but I still want to maintain good driveablality and towing since I take about a 1000 mile round trip once a month. The truck has a 6 inch lift with 35" tires so I need t keep the torque. The only things I have done to it now is a ram air hood and intake, a throttle body spacer and a edge cs tuner. I have always kicked around a whipple charger but havent been able to comb out my pockets to buy one. I know this costs money but I don't want to get crazy.

 

Get a custom tune and a set of headers

 

A small cam will help. The 212/218 is a popular choice for towing apps and you can still use your stock stall converter. Some longtube headers if your state allows them. And of course a supercharger. Every now and then a radix charger comes up in the for sale section on here. keep an eye in there and you can pick up a great unit pretty cheap. And sell the pos Edge and get a real tune. Someone like Blackbear, nelson, or wheatley can get you going for the tunes.

 

Put a chip in it..