Tryin to figure out if one of these headers perform better than the other. Seems that the ASM's are dyno proven...I've read numbers ranging from 15-22hp and similar torque gains. Plus, alot of guys have them and love them...the coating seems to be the only negative, which isn't that big a deal to me (can always get them re-coated). Haven't seen much on the StainlessWorks though, just the article in GMHTP , which claimed gains of 9.8 HP and 10.3 lb-ft of tq....and some nice pics that moregrip provided....definitely purdy.

There's obvious differences just by comparing the two...while the SW tubes seem longer, the ASM's seem to have more equal length tubes. The SW's are available as a complete bolt in unit with catted or Off Road Y-pipe...but nobody is still 100% sure that they'll even fit a 99 (although it appears that they do).

Basically, I'm trying to decide between the two, so I figure that I'll let performance be the deciding factor. If anybody has any dyno numbers of either or both that would be great! Any other input or insight is also welcome!

Thanks!
Billy

 

i'm not sure if you offroad or anything-
but stainless doesn't appreciate going hot to cold quickly.

 

Don't rely on HP/TQ figures alone. Every truck is different due to many factors. One truck may have a 'magic' motor and perfrom better then others, dyno's differ by a lot!, and header designs are an art.

One header may mack more peak HP, but what about the area under the curve? A broad curve is more important to me for a daily driver, then a peaky curve.

So keep an open mind and don't go by numbers alone.

 

Its probably going to be pretty tough getting info on these especially head to head. Most here go with Pacesetters even if they already had longtubes. I know the ASM's have a 2 1/2" collector as do the Thorleys and the Pacesetter's have 3". I think most here prefer the bang for the buck arguement. Lets say the ASM's make 4 even 6 hp more than the Pacesetter (I would find that very hard to believe as the Pacesetters are an awesome header) The $300 difference could buy you a cam to go with the pacesetters...... Way more power for the same money.

 

Thanks for the input so far guys! A couple things that I have to take into consideration: 1) I have a 4x4, so unfortunately PaceSetter is out 2) I have to pass NJ visual inspection, so there has to be room to bolt something that at least looks like a cat converter behind whichever LT I go with 3) Eventually, I plan to have an LQ9 stuffed under the hood, so I want a header that'll let it breathe out as much as possible on the street. Still haven't heard of anyone bolting the SW's up to a 99-02 4x4 yet either...97AGGIE reported that they will fit an 02 2wd HD, but that's a tad bit different. As far as I can tell, they should fit (EGR and AIR isn't an issue for me)

 

Also the coating on the AS&M arent that bad you just gotta keep them out of the salt on the road when it snows mine still look damn good.

 

Ohh..... thats right. That makes it a little more difficult I suppose. I know ASM makes some great headers and if you are going to stay N/A a 2 1/2 collector should be fine. I would go with what you know will fit.

 

whats wrong with pacesetters and 4x4?

 

They won't fit 4x4's...some sort of clearance problem. They've been saying that they're working on them forever, but still haven't released them.

 

do 2wd trucks have torsion bars? Maybe that is why.

What takes so long to work on. If you are really stumped, go buy a set of the competitions headers and see what they are doing that makes them winners and you losers.