OK, so I'm trying to deside between the SLP's and ASM's 1-3/4" Mid-Length Headers and I need opinions on the following (and anything else I've missed). I'm leaning towards the ASM's because appearently the price although higher includes, gasket, hardware, coating...

Fit and finish
Installation (Ease/Difficulty comparison)
Plug Access (difference over stock or each other)
Completeness of kit (what don't they include)

Thanks.

 

I love my AS&Ms!

 

SLP's are mandrel bent .055" (409) wall thickness stainless steel.
ASM's are 14 gauge steel. Both have 3/8 flanges and are a 4 into 1 design. I would rather have the stainless steel. Form what I understand performance is close so look at price and quality. SLP gets my vote.

 

I can't give you a comparison, but I can say that I'm more than happy with my SLPs. I bought them used, so I don't know what comes with them. Keep in mind that they are stainless steel, and don't need to be coated, unless you just want it. Also, I would trust fel pro gaskets more than what comes with any set of headers.

Here is what I bought for my install
Autozone header bolts $3.99 baby. Torque them once, torque them twice and you're done!!

Fel Pro gaskets, also bought high temp RTV(orange) to smear on them to prevent a blow out.

The install was pretty easy. One bolt behind the alternator was a PITA. Also, the last one on the drivers side. I didn't have to jack up the motor though.

Good luck on your decision.

John

 

I have had the AS&M headers installed for about 2.5 yrs now. They were a brutal PITA to install. Plug access is very challenging.

However the build quality is very good and performance gain was also pretty good. I've had no problems with the finish on the headers after about 40,000 miles (no winters and not too much rain).

Mike...

 

SLP's definetly get my vote, also if you buy the SLP spark plug install tool the install of spark plugs is a breeze, the headers never had the slightest rust nor did the Y-pipe, both are excellent fit & quality, just needed to take the steering columb out to install them, but hey I need some challange

 

You took the whole column out I just had to disconnect the steerring shaft, two bolts!!!

John

 

i hear plug access sucks on SLP
and SLP's customer service sucks too

 

AS&M ALL the way. The steel grade is better, everything although not stainless steel comes HPC coated INSIDE AND OUT, including the Y-pipe that comes with them. HPC coating is substantially better than jet-hot from what I've read.

Furthermore, the AS&M's made 40+ HP MORE than Hooker LT's on an engine dynoed at over 900HP by Injuneer.

In other words, the AS&M's produced 40+ HP more than the hooker LT's until around 900HP, which you won't be anywhere near pushing anyway.

AS&M's are better than anything SLP puts out IMO, it seems like people worship SLP despite their shoddy CS and poorly constructed parts.

People can't even get an intake from them in under 2 weeks.

 

Another AS&M vote from me. Great fit and finish. No regrets.

 

I tried to get the Arizona Speed & Marine headers, but cancelled the order after waiting for 3 months. I got the flp's instead, am very happy with those, excellent setup.
As far as the ASM on injuneers car, those were modified to resemble longtubes. The ASM as supplied would probably be unable to support 900 horsepower.
I would suggest getting the ASM headers over the SLP's.

 

In the interest of accuracy.... the dyno test I mentioned was on an 850HP Vortech S/C'd 383 used only for 1/4-mile trips. The AS&M's made at least 40HP more than the Hookers. But that was on an engine that never operates below 5,000rpm. They didn't even start the logger on the engine dyno until 5,000rpm. And LT's would probably provide more low end torque - important in a street engine. I'll sort it out, if I ever get the Hookers on in place of my AS&M's (the same ones used on the tests)..... I generally dyno both NA from 2500-7000rpm, and on the spray from 5000-7000rpm.

With a bigger cam in the S/C'd 383, and making over 900HP, the Hookers made more power. Hard to explain why. That's why you dyno.... .

The collector on my drivers side AS&M has been modified to point straight back, like an LT, and all engine dyno pulls (both the S/C'd 383 and my engine) were run using a custom 3" Mufflex Y-pipe, with a Borla XR-1 shorty muffler in place of the cat on each branch of the Y-pipe. And then connected to the shop exhaust stack, to simulate the fact that both cars also ran 4" Mufflex catbacks.

S/S is good, because it reduces corrosion. But true Cerametallic coating, like HPC, Jet-Hot, Airborn, etc., applied to the inside and outside of the primaries, reduces corrosion, reduces stress cracking, reduces underhood temps, and increases HP due to improved scavenging. If I was going to buy the SLP headers, I would still get them coated......

 

i have the SLPs and i will say they denfinitely arent engineering marvals. plug access is rather poor. installation was difficult but doable...i could probably do it in 6 hrs or less with a friend now after installing 2 sets. now they are stainless steel but dont let that fool you because youll want to get them coated or they will look pretty bad after a short while.

in conclusion.... if you are getting them new then get AS&M but if you find a new used set of SLPs for $400 id jump on them.

 

Gentlemen,

Thank you all very much for your input, I really appreciate you taking the time to respond thoughtfully and completely. I will probably wait and save the extra dollars to afford the ASM's (too bad I didn't have the money last month so I could have saved 10% from Tbyrne).

Later

 

yea that 10% is worth it, i'd wait till their next 10% off sale