Squeezing Performance out of the 5.3L

i used a tb spacer on 01 suburban and could tell helped on power but reduced milage slightly but that might have been my fault  heavier foot and all hypertech power progIII changed to H rated tires in program gps showed 128 MPH after spacer and 113 without  

HEY,
I GOT AN 05 SILVERADO 2WD AND ALL I DID WAS PUT IN:

-k&N COLD AIR INTAKE
-THROTTLE BODY SPACER
-AND A BADASS PAIR OF FLOWS
-HYPERTECH PROGRAMER
WHAT REALLY MADE A DIFFERENCE WAS THE COLD AIR INTAKE SYSTEM
I HIGHLY ADVISE YOU PURCHASE A COLD AIR SYSTEM FOR IT.
I GARENTEE IT WILL WAKE IT UP. MOST LIKLY ABOUT 12-15 HP AND ABOUT AN EXTRA 10 LBS OF TORQUE.  

hey bud best bet, get rid of that TB spacer and hypercrap, get a custom tune. and never run shorty headers, they flow almost identical to stock. my 5.3 put down 341rwhp, had a mailorder tune from a reputable tuner, comp cam, longtubes, 3600 stall and 4:10s, im not saying do all that but I picked up 6 tenths of a second in the 1/4 mile with my custom tune over a hypertech, ive got alot more down now but that is where i started.  

Question i live in the worst state for modifying my 06 5.3L sierra, I am trying to upgrade performance, I already have a K&N cold air intake im looking into the tuner from black bear performance, my issue is I have yet to find a long barrel header that is legal and if i cant is the shorty sufficient for gains or is it best just to leave it factory? Also what would be the best exhaust to put on it for gains and for it to have a good growling sound  

being from california i understand your frustration. i would look for a set of mid-length headers to stay leagal. and 40 series magniflows sound pretty good on my 03, and there was definitely a noticeable increase in power. and if you can keep your foot out of it and increase in mileage as well.  

being from california i understand your frustration. i would look for a set of mid-length headers to stay leagal. and 40 series magniflows sound pretty good on my 03, and there was definitely a noticeable increase in power. and if you can keep your foot out of it and increase in mileage as well.  

Hey all, some interesting ideas so far. im building up a 5.3 to throw in my 67 c10 and am looking for some easy performance gains before i tear into the internals and come out with a 383ci. i am wondering if there is a cam, heads, and intake i can run for my 5.3 now that will be suitable for the 383ci later. also going in is custom ram-air induction system, some long tubes. strait exhaust. maybe with some glasspacks...  also im looking for a decent 5 or 6 speed manual tyranny that will hold up to a bit of abuse and some towing.  

What year truck do you have and what exactly did you do to the truck? I have an 04' stock 185,000 highway miles. bought it new but now would like to do K&N cold air, Flowmaster cat back exhaust and hypertech max energy programmer. But I'm trying to figure out best money for fuel savings and hp gain?? any thoughts or suggestions would be greatly appreciated.  

Hello, and yes Im a new member. I have a 2001 GMC with the gen III 5.3 that I have been dableing with over the years with bolt-ons. As far as headers the long toobs seem to give me more power. I have a friend that has the same engine and he went with the short and we both agree that mine feels like it has more power than his after the aplication. I could really tell a diff after the air filter change as well. Going with a cold air intake was just remarkable. I have heard that also changing the thermastat to trick the computer into thinking it is running colder than what it really is. I dont remember if it is a 160 or a 180. I believe that the stock one runs at 220. I believe that you have to have a power programer for this to work correctly. I will find out and post info.  

I also have a guy in east TX. that does a great rebuild on the trans. Deaper pan, stronger pump, heavier 2nd and 3rd clutch bands and minor modification for a harder shift. I watched him doing what he called the equivalant to a shift kit. He drilled a hole on the hydrolic housing in a certain place dont ask me were and was able to remove a pin. He put another one in and I dont know if it was shorter or thinner but the difference when I took off was that the RPM's went from shifting at 26 to 34. And when the tow hall was on shifted at 38. It would almost turn the tires over not getting on it. A very hard shift. Usually you would take the shift plate off and drill the fluid holes out to 7/16ths. This allows for more fluid to pass and this is basically a shift kit with out buying one and using what you already have.  

Im a flow master kinda guy. Turn them down right off the flowmaster. Running them duel out the back cuts down the noise if you like that. Turning the duels down underneath the truck, the sound bounces off the concrete and sounds best to me.  

A New Poster here, with a 2003 Chevy Avalanche 5.3L

I am finally going to do something to address the poor fuel economy of my 2003 Avalanche 5.3L......12/city/14 hwy.

Tell me if I'm headed in the wrong direction, please. I plan to install a cold air intake, a throttle body spacer, a performance chip/programmer, and finally, an exhaust, either flow master duals or magna flow.

I've recently been told that a CAI won't work well with the super chips programmer. Also, that even a K&N filter might not complement the super chips programmer. So do I skip the programmer or the CAI and spacer?

I'm wondering if I might get the same fuel gains just by going with the CAI the spacer and the exhaust?  Or maybe just the programmer?

Any advise is welcome. I don't want to get into cams and headers.  

Thanks.
Joe D.  

I have done tones of research on headers. JBA seem to be the best but you will need to re tune your truck and possibly upgrade the wires again. You will see a 12% upgrade in efficiency. Shorties are what I would go for. They are more catered to getting off the line. While the long tubes are top end. All in all headers are my final upgrade and it will be the most effective upgrade for your truck.  

I'm new to forum and was looking for some advise. I am in the process of putting long long tube headers and exhaust system on my 2007 gmc. Sierra it got the 5.3l flex fuel engine. I also plan on getting a full cold air intake. Can you please recommend a compatible Cam (mild) for extra performance. I was trying to stick Gm parts this a daily driver I was trying to keep it reliable. Or is it even going to be worth it?? Want more power mainly.