Headers for Vortec 5.7

carl722 · January 15, 2004

Does anyone have headers on their vortec 5.7? I want to find a set that will connect right to my exhaust pipes that were connected to the manifolds. According to the desktop dyno this would be worth over 30 hp to replace the manifolds with headers. I don't have the O2 sensors in the manifold they are in the pipes on both sides of the cats. The cam I have with the headers should push me over 474 lb/ft and 400 hp. That should be able to make a heavy Z-71 put a Hemi Ram in the dirt after I get my dynotuned program put in the PCM.

LS1Steve · January 15, 2004

i'm shopping for them too, pretty much have it narrowed down to the JBA or Edelbrock. They both make shorty's that bolt to the stock cats in stock position.

I think your hp estimates for your cam are a bit optimistic though, a cam definitely doesn't add a hundred horses. I have a pretty aggressive lopey cam in my camaro and it only gave me about 50, and that was with higher ratio rockers/springs. Heck my Z71 w/vortec5700 isn't even at 400hp, and i have a whipple!

99-2door · January 15, 2004

Yeah I don't see pushing that kind of torque or HP without some major mods. Heck I am building a 383 out of a Vortec 5.7L and I wasn't expecting near that much torque.

I could go on about that all night, but........ I have been wanting to look into headers as well. I would be interested to see what people have been using and any problems they might have had with them.

vortec350 · January 15, 2004

I have hedman shorties on mine for over a year now and absolutely no prblems.I love them and would get them again.Check them out also.

sunbiyatch · January 15, 2004

i also have a 5.7 vortec and i was looking into hooker competition or super comps

redchev · January 15, 2004

I had edelbrock shorties on my 1994. I went with them because they only use stainless for fuel injected engines. They were a perfect fit to the stock y pipe and came with all the correct hardware. No problems the 2 years I had them.

Mule · January 15, 2004

Have you looked at Banks? I love mine (though non-Vortec)

http://www.bankspower.com/System.cfm?appid...AC03&sysid=SC04

All Banks pieces can be bought seperately, but they work best together.

badass96z71 · January 16, 2004

i bought a pair of JBA's fro my '96 5.7 vortec. stainless 409 ceramic coated cost about $680 out the door, no problems yet but didn't give me the sound i was hoping for.... I wanted to go with the banks headers but they run about $900 a pair, but they have a 5/8" flange and claim to be leak free even without a gasket. If my JBA's ever go sour i'm going with banks....

carl722 · January 16, 2004

I think I'm going to buy the Edelbrock or Gibson headers. The Edelbrock are much cheaper though. I ran my cam specs through the desktop dyno 2000. I downloaded the cam files and head files for the L31 heads and put the combo with headers and a 9.5:1 compression and I come up with 404 hp @5500 rpm and 443 lb/ft @ 4000 rpm and at 2000 rpm 365 lb/ft. This is crankshaft horsepower not rear wheel. They are rating the engines from the manufacturers at the crankshaft again to inflate the HP numbers because HP sells vehicles. I do have to go to fastchip (Ed Wright) in Tulsa for hiim to put the truck on the dyno then write a program for it then back on the dyno to check the improvement. Without turning up the fuel flow and timing to match the cam I don't get much performance gain until the PCM knows how to run the engine. I also put a helix throttle body spacer on it.

99-2door · January 16, 2004

I think I'm going to buy the Edelbrock or Gibson headers. The Edelbrock are much cheaper though. I ran my cam specs through the desktop dyno 2000. I downloaded the cam files and head files for the L31 heads and put the combo with headers and a 9.5:1 compression and I come up with 404 hp @5500 rpm and 443 lb/ft @ 4000 rpm and at 2000 rpm 365 lb/ft. This is crankshaft horsepower not rear wheel. They are rating the engines from the manufacturers at the crankshaft again to inflate the HP numbers because HP sells vehicles. I do have to go to fastchip (Ed Wright) in Tulsa for hiim to put the truck on the dyno then write a program for it then back on the dyno to check the improvement. Without turning up the fuel flow and timing to match the cam I don't get much performance gain until the PCM knows how to run the engine. I also put a helix throttle body spacer on it.

Manufacturers have never rated HP at the rear wheels. They rate it at the crank with accessory load, aka net HP. Back in the day, early 70s it was rated Gross HP, which was the max they could get the engine to put out at the flywheel with no load and ideal conditions. I assumed that you had gotten your figures from Desktop Dyno. A lot of people have desktop dynoed their way to 400HP.

Just seems a bit unrealistic to me. I don't doubt your figures, but I think you may be a little dissapointed when you hit the real dyno. No doubt your engine is much stronger than stock though.