Dont waste money on pulley or TB mods, untill you have done every thing you can and are still looking for alil more. The $ per HP gain is just not worth it.
Your next step is cam/springs and a converter.
Cheapest is a Z06 cam and the yellow behive springs that go with it along with the 7.3 or 7.4 pushrods. forgot which atm, its spammed all over the truck sites. This cam is the stock cam in the vettes, it has silky smooth idle but makes gobs of power over the truck cam you currently have. Noone but you will know its in there.
Total cost for those 250 MAX used.. most the time the springs sell for 20-40$ used, considering they can be bought for 55$ + shipping new..
Cam usually runs 100-150.
Look to LS1tec, LS1truck and performance trucks.net for these mods.
Guys over there are dumping them everyday.
You will notice a nice improvement from them, Yess you must run the yellow springs, and you can change them with heads on the motor.
Next step is a re-stalled Trailblazer Inline 6 torque convertor.
Can be bought new from Circle D for aprox 350-400$
Or new for aprox 150$ and re stalled by your choice of shop..
Circle D's I6 convertor flashes around 2800-3000 depending on motor config and what you tell them when you order it.
You can tow all day on it aswell.
Peep this.
Pop those in before you get your tune and you will be Realy happy!
You are probly already beyond acceptable injector duty cycle. start looking for the 8.1 liter injectors.
Beyond that is
heads (notice these heads already have the springs you need., gears and bigger cam.
Take a look at your heads, passenger side one, right at front below valve cover will be a embossed number, 243, 317, etc. post it up here
Circle D is having 5% off BF sale...
A setup to go with a much larger cam, its always better to plan ahead with valve springs, then having to swap them twice.
This will take ya from a 5.3 to a 5.7 LS1
6.0 LQ4 pull out
Vinci Trucker cam and comp springs
Winner winner chicken dinner!
