I have an 03 expy with the 5.4L engine and want to know what the best performance mods are for the dollar. If you can tell me what items you recommend and how much hp/torque difference I can expect I would be grateful. Also, what would this translate into for 1/4 mile times and what is the 5.4 expy at in the first place for the 1/4. I think acceleration is a little lacking so I am hoping to get it a little better. A supercharger would cure things but I am not sure if reliability problems and cost are worthwhile. I would not want to take any big risks at all as I don't want to ruin a $35K truck or create more headaches. Reliability is foremost for me with performance next.
Also, is there a good place to get used or clearance performance parts for the truck where I can save some money. I could spend $4K on a supercharger system but then I look at that and that is $4K I could have spent on something else (a motorcycle for instance). I normally like to buy something with all the performance I am going to need so I don't have to sink $$$ and have warranty/reliability problems later but nothing offered really has that great of performance. Chevy Suburbans have the 8.1L for instance but they are more expensive and I like the independent suspension, fold down seats, etc of the expy. It is always a trade off but if I can spend a reasonable amount on my expy to get it more tolerable I would certainly consider it.

Thanks

 

Supercharger is the best bang for the buck.Just keep the boost low 8-10 lbs. Antything else like nitrous will hurt the bottom end.Check out PowerDyne,,cheap or Kenne bell twin screw (low end torque booster)..