I’m looking to put some headers as a performance upgrade as I plan on doing a 383 build later down the road on my 94 LT1 while still keeping the cats somewhere in the system as they’re required for emissions in my state and county(NC varies from county to county). I haven’t been able to find a catted x pipe or anything of the sort that would work with long tubes.

Any help would be much appreciated.
Thanks, Grayson.

 

I don't live in your state but I would check to make sure you know the local inspection laws, what they'll allow, and what they'll reject. Years ago, I read federal law mandates keeping emissions devices in OEM locations -- in addition to having them. By THAT definition, it would be impossible to install headers as convertors would need to be moved. So, unless your response comes from someone in your state, double-check to make sure feedback is valid.

In general, people with LT headers place cats immediately "on" the end of the headers. "Bullet cats" is what they are called. They need to be AT the headers so they'll get hot enough for their "chemical" reaction. (They convert "toxic/poisonous" fumes to "less-harmful" fumes). Mufflers sometimes have "X" pipes built-in. Convertors are rarely part of another exhaust component though I'm thinking they are built into ZR1 exhaust manifolds -- as they are on some other car models. Maybe ZR1 manifolds might be an option? Never heard it mentioned. Stock LTx manifolds aren't terrible -- for those living in states that won't allow VISIBLE alterations. Sniffers would the other obstacle.

Even with laws in my state, I try to keep mine running as clean as possible.

 

I did some more research and I found that in NC, they only need to pass a visual inspection and if it’s 20 years or older then it’s not required for the “onboard” emissions test. With that being said, I have to have them, working or not. That’s as far as I’ve read into it. When I bought my 86 K10 from a guy in the neighboring county that I live in about 2 years ago, cut the cat out and had its final inspection and it passed.

 

Checkout the American racing headers long tube systems. It looks like you can maintain the factory AIR/EGR and you have the option of cats or no cats with them. 1 3/4 primary tubes into 3” collectors to a catted X-pipe. Bungs for O2 sensors are there as well. Definitely check into your state laws to make sure it would be street legal. I live in NJ and no inspection is required for older than 1998 or basically any OBD1 car. No safety or emissions at all for me.

 

Thanks for posting this. When catted x-pipe was mentioned, I was thinking of mufflers where an x-pipe is built-in (internally). I hadn't considered a "pre-assembled x-pipe - bullet cats combo! Duh. Maybe because the pipe spacing can get ":dependent". Seeing the ARH setup, I have to confess my curiosity with the 02 bung and cat locations. Both are quite a bit further downstream than "normal". Gotta wonder how that affects operation of both? Especially when builders traditionally want the 02 bung IN the header pipe....as mine is. I gotta think they don't want to "interupt" header scavenging that's still a function of the 20-24" collector length (I've seen mentioned in recent reading).

In case the OP doesn't know, TPIS has always been at/near the top of the list for C4 headers. It's too bad Vette-Tech went out of business. They used to make 4-2-1 headers (which I have). I haven't looked recently enough to know if Exotic Muscle is still an option? Took a quick look on eBay (as there used to be some well-priced "off-brands"). First thing I stumbled across was a set claiming fitment for 92-96 LTx models....but they had the L98 air tubes! LOL

 

I agree. The last time I was on TPIS, it said the headers were unavailable. The good thing about really any exhaust is that you can drill a hole and weld a boss/bung anywhere you want for upstream O2 sensor, etc. I really like the ARH system, and it will probably be my choice when it comes time for me. There are more than a few threads on here about them and all say positive things about fitment, etc. many have said good things about the TPIS and Exotic Muscle too. Some of these older items pop up on eBay and on the forum now and then. Worth picking up even if they need some clean up and a coating.

 

Also, I’m not 100% sure but it looks like there’s a bung in the collector and after the cat on the ARH system.

 

Not sure, but I think Melrose makes a kit for the lt1? I have their system with the x pipe (not an lt1)

 

I believe melrose stopped selling/producing the headers. They may still produce the exhaust portion itself however.

 

I've been searching for a while and finally purchased a pair of ARH, American Racing Headers

You can order with Cats and or emission connections, checkout their web page. After give them a call.

However in my '87 which is a convertible, Cats will not fit My C4 because convertibles have a X Frame Brace under the body.

I will be starting a post on My installation in a few days, time permitting.

Michael
.

 

Awesome! Looking forward to seeing your new set up. I think the ARH is the way to go and what I’ll be doing on my 95 coupe when the budget allows. Keep us posted.

 

Will do

Michael.

 

I found a used pair of TiPS, which I simply bolted straight onto my stock system (CAT deleted), and I plan on getting the Melrose (?) X-Pipe resonator. Really like the set-up, just for another "real-world" opinion.

Ronn

 

The TPiS are supposed to be really nice and fit really well. If I came across a nice used set, I’d definitely consider them as well. On their website it says unavailable right now. Not sure if they are going to still be in production or not. Do you happen to have any photos of your set up or could you post some when you’re back under there for the x-pipe install? I’d really like to see it. Getting a used set and a good x-pipe is just as good and probably a lot more cost effective. The ARH system is really nice but the price tag is a little steep for me personally.

 

Ronn, is this on a 93 LT1 car?

 

yessum😎

 

I like that the TPIS have the bolt spacers on the flange. Makes getting the wrench on there a lot easier it seems. I think I’d like to score a set of used ones myself. With the 1 3/4 primaries, 3” collectors, and ceramic coating they have all the features I want. I looked at the Melrose x-pipe set up and I really like that too. I think you’re on your way to a really nice set up.

 

For those interested in achieving the extra tenth, the TPIS headers are not equal length, the ARH headers are. It will make very little difference on a street car. I'm running ARH headers and they were worth .15 in the quarter over Hooker Super Competition headers.

 

383 speaks true. Never had ARH, but the TiPS allow easy access to plugs and filter-- ARH might too.

Ronn

 

Sorry for the long post but I have had my ARH 1 3/4" headers, bullet cats and X pipe for several years. They are on my '96 and are holding up very well!
Installation was not difficult but back then there were no instructions, and no header bolts included. On my '96 there was a bracket at the back of the alternator that would not fit after the header installation. I had to cut, weld and change the angle of the bracket to make it fit. ARH said to just leave the bracket off.
Leaving it off may have been fine but I figured GM tries to save a dime everywhere so if they installed it then the bracket should probably stay.
Also the catalytic converters are located further back than the stock cats. This new location puts those hot cats very close to the floor. I could just about stick a finger between the bottom of the floor and the top of the cats. ARH told me that a fingers width was fine. I decided it wasn't. So I purchased Thermotec stick on heat barrier to the floor above the cats and fashioned two stainless steel plates that mount over the cats.
The air injection tubes fit fine, the four O2 sensor bungs worked fine. I did require an extension cable on the passenger side to connect the after cat O2 sensor. I called ARH and they sent me one free of charge asap.
Again there was a bit of hot rodding required for a real clean installation.
ARH was there to answer technical questions, the headers are designed pretty well! Spark plug clearance is just a bit better than stock but not by much.
Other things you may want to do are; install Thermotec heat barrier around the brake power booster, and also around the high pressure A.C. electronic switch. On my 96 this switch is very close to the header tube. After five years the switch fried and threw codes for a low 5V reference voltage. My car ran terrible. Turned out the switch which has a circuit in it had a shorted IC which dropped my 5V reference to about 2.8V.
This took me a while to diagnose even with a shop manual as it is not a common problem.
Good luck on your selection ?