I have an 03 silverado with a 4.8. I've installed a cold air intake, electric fan, bullydog tuner and true dual exhaust with some flowmasters. Originally I had an h-pipe, but I recently installed qtp electronic cutouts with an X-pipe. As you know the 4.8 lacks low end torque and I'm thinking the h-pipe gave better low end torque. I'm shopping for headers now my research shows that though long tube headers give more power, short headers give more low end torque.
I do plan on upgrading the cam, MAF, throttle body, stall, 410 rearend and a professional tune after each major engine upgrade.

 

These are what I'm putting on next. i'm pretty sure there a sponsor on here to.

Speed Engineering Shorty Headers Truck & SUV (1999-2013)

 

Go with the 1 3/4" speed engineering long tubes when the come back in stock.

The shorties have been proven to provide very little to no gains.

 

Remove the MAF and throttle body from your mod list.

Those are only items you replace when you outflow them. No way a standard cam/headers build will outflow the factory MAF and throttle body.

 

Apparently you have this thread posted twice.... I respond in the other one!!!

 

There are a handful of seasoned veterans in this forum (more than all other forums specific to late model GM 1/2 ton trucks that i have personally had experience with) and ive read almost every thread on headers here, lol. I dont recall any of them recommending shorties over long tubes for ANY LS V8 engine. Now i would definately be looking for 1-3/4" primaries for a 4.8 but thats about it.

Plus, if youre doing a regear to 4.10, you just made a huge improvement to your bottom end grunt. You didn't add torque but you just made the torque you do have work for you much more than before.

 

What maf will flow more??? From what i understand if you out flow the MAF its time for speed density.... Which from my understanding any sort of FI you want to go SD anyway....or am i misunderstanding something there???

 

You'd change the size of the MAF, thats what I mean by outflowing. You are reaching the max Hz level of the stock unit.

Just say it's a 500 cfm max that can flow through the stock diameter MAF, you upgrade to a 650 CFM housing. If at 500cfm you have 11,500hz on the maf, then at 500cfm through a 650cfm MAF housing, it's only 9,500hz. I think I'm explaning this correctly. My example likely sucks.

But I've never really looked into who makes a bigger MAF sensor, but I think texas speed does.

 

Well there are two reasons why I decided to go with the shorties. First I was told not to remove my cats unless I was blown or turbo'd and 2nd because it cost an *** load for the y pipe with the cats and while I'm at it unless your spinning the **** out of your engine ever single time you drive it you will never tell the difference. now that being said why not just keep the stock manifolds then right? well in my case looks.

 

I remember seeing a granatelli that was supposed to be a high flow maf that was larger than stock, but everything ive read they are about worthless!!!