Header options for 96 LT1 with manifold cat?
 

I originally wanted to get shorty headers, assuming they'd be a direct bolt-on. This was until I figured out that I would have to cut and clamp the flexible section of the factory pipe.
I'd rather not do any cutting myself. The last time I tried to cut off behind my cats (mustang) to gut them, I ended up dragging the exhaust along the road all the way to the exhaust shop. :P I have used this inability to DIY exhaust as my excuse to reconsider mid/long tubes.

What all would be needed for a successful Mid/Long tube install? Headers, and Y-Pipe? The 96-97 have that annoying cat directly below the manifolds, so i know this complicates things.

Are there any reputable/mainstream exhaust shops out there that will touch the headers if aftermarket mid/long tubes are going on? I have read they can be pretty anal. The one I went to charged me up the behind to re-weld the cats on my stang because they thought i attempted to gut them. I hadn't at the time, but there was a chunk missing from one of them. Or is it possible to find a DIY long/mid tube solution without cutting, or welding?

Would this be my basic required parts list?
Amazon.com: Pace Setter 70-2237 Painted Long Tube Exhaust Header: Automotive

Pace Setter 82-1161 Off Road Y-Pipe : Amazon.com : Automotive

Re: Header options for 96 LT1 with manifold cat?
 

What emissions do you need to meet? The "off road" Y-pipe eliminates AIR, EGR, after-cat O2 sensors and the cat. You seem to indicate you want to use cats?????

What system will you be using after the Y-pipe - stock intermediate pipe or an aftermarket intermediate pipe? Going up to a full 3" IM pipe is almost mandatory.

The picture of the Y-pipe you linked is not actually a Y-pipe. That's an X-pipe, and would be used with true dual exhaust from the X-pipe on back. When it says that "extensions connect to stock exhaust", that is not correct, for the pictured product.

I would also suggest you take a serious look at cera-metallic coated headers. The coating is applied both inside and outside the tubes, and 1) reduces heat loss to the engine compartment, 2) gains a couple HP through increased scavenging due to keeping the heat in the exhaust gas, 3) reduces/eliminates surface corrosion on mild steel headers, and 4) reduces weld thermal cycle stress cracking. The paint on painted headers will burn off in a matter of minutes, and they will start to oxidize (rust).

The photo of the headers is also a bit screwy - the two black pieces are OK, but they include a third piece that appears to be an emissions compliant shorty header for the driver's side.

Re: Header options for 96 LT1 with manifold cat?
 

I am in Florida, so I don't have any emissions to meet. It just seemed easier to leave it all there if I was going to attempt to install myself. If I did go with an off-road pipe would I have to remove or tune out the components you mentioned?

I would have been planning to use the stock intermediate pipe. I didn't realize an intermediate pipe was mandatory.

My brother had a set of painted Flowtech headers on his 73 camaro, and, sure enough, they rusted relatively quickly. I didn't think about that. The difference in the coated pacesetters isn't that insane.

I don't know whats going on with that pic. I thought they were shorties when I first saw them. Jegs/summit just show the 2 headers, without that extra chrome section.

After reading your post, it seems that a single cut for the shorties is a better option than what is involved for long tubes. I know they will flow, and sound much better. I doubt I can do the labor to install them, and I also doubt that any exhaust shop will be willing to touch the stock catted manifold. I think that virtually all long tubes would not qualify as emission legal on the 96-97 Z28, based on the stock manifold design (cat).

Re: Header options for 96 LT1 with manifold cat?
 

Correct - all long tube headers are not emissions legal on an LT1, because they violate the Federal law that says the catalytic converters can not be relocated, and the number of cats cannot be changed. Depending on where you live, the Federal laws may or may not actually be enforced. In some locations, if your exhaust system has at least one cat (93-95 non-CA) or two cats (95CA - 97) they will overlook the fact they are not in the stock locations.

You will get better results with long tube or mid-length headers. Shorties seem to produce somewhat limited increases. I had some JBA shorties on my car right after I bought it new, and they provided a decent bottom end increase, but they actually seemed to choke the exhaust at high RPM. I currently have a set of AS&M mid-lengths that have been modified to delete the Y-pipe, with the driver's side collector pointed toward the back of the engine, rather than pointing toward the engine so the Y-pipe can wrap around the front of the oil pan. They were dyno tested on a friend's car, and provided better gains in the higher RPM range than the Hooker LT's they were compared against.

You seem surprised that the stock IM pipe needs to be upgraded. Ask anyone for the first two mods on an LT1, and they will tell you a CAI and a 3" catback. There's 25-30HP just waiting to be grabbed. Throw in a PCM tune and pick up another 10-15HP.

Re: Header options for 96 LT1 with manifold cat?
 

Ok then, that's what I thought. So an exhaust shop doing much of anything would be out, short of maybe if I took the tags off, and towed the car there as a "race car" :P

I really don't mind losing top end power, as the massive low end torque my previous 94 Z28 had, is the main reason I decided to get another LT1. I drove my brother's 98 Z28, and it's just not the same down low. If shorties increase low end, I sure won't be complaining.

I found a local craigslist seller offering a set of used SLP shorties for 96-97, which supposedly will bolt up directly to the factory pipe without cutting. They use 1 3/4" pipes, rather than the standard 1 5/8". I might go that route.


As for the IM pipe, I think I was confusing it with a different part of the exhaust. If it's the pipe that goes from behind the cat, where the exhaust goes back into a single pipe, to the muffler. Yes, of course I would replace it as part of a cat-back install. I have never thought of it as the intermediate pipe, though.

Re: Header options for 96 LT1 with manifold cat?
 

Really depends on the shop. I've had a couple systems built for my car, and the shop was willing to do anything I wanted. And this shop is a top supplier of LT1 systems. Check around with other performance car owners in your area and see who will work on your car, and install the exhaust system you want.

My personal preference is to keep it "legal" in the sense that I can pass tailpipe emissions... not with respect to whether all the parts on my car are CARB approved, or in their stock position. We designed a system using a 4" Mufflex catback, and 3" Carsound dual cats with bolted flanges so they could be removed for the track. AIR, EGR and EVAP were all kept intact. It's a 500HP engine that would pass tailpipe emissions. At the track, with a 300-shot and heavily leaded fuel, the cats dropped out and a pair of Borla XR1 shorty mufflers bolted in their place.

Again, the SLP 96/97 shorties are most likely the CARB-EO approved headers (totally emissions legal), and not really a good choice for any reason other than that. The driver's side primaries have to snake up over the top of the valve cover so they can join together before the cat in the stock location. Pours a lot of heat into the engine compartment, and they aren't going to perform as well as a set without all the twist and turns in the primaries.

And don't rule out simply installing the headers yourself. It's really not a hard as everyone seems to make it out to be.

Re: Header options for 96 LT1 with manifold cat?
 

This is wrong. You are thinking of AS&M shorties. I have the SLP shorties and they don't come over the valve covers at all. None of the primary's come near the valve cover. They run to the side of the engine.

Re: Header options for 96 LT1 with manifold cat?
 

You're correct - I was thinking of the AS&M's. Been at least 10 years since I've seen either. The SLP's do sweep upwards, and the compormises made on the drivers side to make them fit up to the triangular flange for the drivers side cat are terrible:

http://img.photobucket.com/albums/v4...headers001.jpg

Re: Header options for 96 LT1 with manifold cat?
 

They do go upward a little but it isn't that bad. I'd say they were the best of the shorties for someone wanting to be 100% emissions legal, like I was at the time.

http://myweb.cableone.net/tta1387/P0002304.jpg

Re: Header options for 96 LT1 with manifold cat?
 

Thanks for the replies. In case anyone cares, I ended up going with the SLP shorties. I don't have to meet emissions, but they are the easiest solution, and the price was definitely right.

More problems, though, so it'll be a while before i can do anything with them. Just found sand oil valley :~(

Apparently a pissed off neighbor of the previous owner must have done it when he had it sitting outside his apartment for days with the hood off. :eek:

I wish I'd at least yanked the valve covers off before I started buying clutch/exhaust/cam, etc... Oh well, I'm sure glad i didn't try to start it.