What's the single best mod for a 5.3?
 

I just bought a completely stock '02 Sierra extended cab 5.3 2WD. I will be using it to tow my race car this year on an aluminum open trailer with a large storage box (car and trailer weight about 4500lbs.). Most of the tracks I will be going to are about 400 miles from my house.

I don't have a lot of money to spend on the truck, but I'd like to do at least one thing to improve the power and/or mileage that the truck will get. What are some of the single best modifications that I can do to this truck to improve power and/or fuel mileage?

a custom tune and exhaust is where most people will start, or a radx? :devil:

you're probably going to see the most gains from some sort of FI. Magna or Radix seem to be the popular choices for something you can do with out a lot of extra work. I think doing a turbo setup would have too many variables for you to iron out to get worthwhile power out of.

or you could do a TC but don't go rediculous with the stall rating since you're towing a heavy car

n20 gives you more hp/tq per dollar than anything else but if your talking about wanting towing power and strip power I would say Turbo then Radix!

Depends on your budget, but I'd look into a single turbo kit. There are LOTS of front mount kits, and the rear-mount STS. If you have the money, can't go wrong with ANY of those kits. :D

If I read your post correctly you don't have a lot of money to put in the truck so I would guess that would eliminate a turbo or SC. That being the case then a tune would be your best bang for the buck. Intake and exhaust catback will buy you very little on a stock engine. Get a 93 octane tune from one of the sponsors on the right---------------------> and you can do intake and exhaust later if you like. A stall is not the best for towing and may limit the amount of weight you can tow without worry.

My thoughts exactly!

Id have to say a Tune also.. Mine really woke my truck up!

Radix

You best mod for the 5.3 is to hang out here and learn.....