My 94 is lowered 2" all the way around and actually I would rather have it lowered then have the headers.
surfer92: Do you happen to have any pictures looking under you car at the collectors? or a picture that could show how low they set? Could it actual be that the LT1 heads set higher then the L98's? Ive been told by many with lowered 84-91's that long tube headers hit the ground. I figured it would be just the same with the LT1/4's.


The reason I'm so worried about the ground clearance is because I just
about destroyed a very nice 99 LS1 camaro. I bought the car lowered and honestly did not realize that it was lowered. I ordered SLP stainless longtube's ($1000) and the Y pipe with two spun high flow cats ($300). I installed them and noticed it would scrape over speed bumps and hit the ground if I hit a hard bump or pot hole. I drove it like that for 2 or 3 weeks waiting on a set of stock springs to come in from ebay. I was driving down I40 and in a 2 or 3 mile section the road has a very high crown. Well I hit it at 70mph ! sparks flying and a horrible sound. The headers bottomed out and drug the ground for approx 300-400ft before I could get it over the crown and to the side. Before I even realized what was going on I heard the exhaust tone change.

I drove it 10 miles back to my house and I could tell it was pure open headers. it was so loud. I thought it had pulled the Y-pipe off the collectors, or push one of the cats back.
When I got home I put it in the air and was sick.. It had removed almost 1/2 of the bottom two tubes on each side of the collector, and the whole bottom of each of the high flow cats where gone. It even sanded down the ceramic.

Knowing I just destroyed the headers, Y-pipe and cats I went to remove them to install the factory manifolds and cats. That when I realized I was in big trouble! Three bolts had snapped off inside the head when it bottomed out. Two on the passenger and one on the driver. I was sick. It was strange. The car only bottomed out the headers 1 or 2 times on speed bumps and large bumps in the road. It did not seem that low at all. I would have never guessed it was low enough to drag the ground that hard on the interstate.

In 20 secs I destroyed $1300 worth of headers and cats that where only 3 weeks old and I screwed up both edelbrock XT heads. I had to remove the heads and take them to a machine shop to remove the broken bolts. I put it back together and sold it.

I don't want a repeat of that to happen. specially over $150 headers. I had gave up on owning long tubes when I decided to lower my C4 until I read this thread. If the headman headers are within 1" of the stock LT1 exhaust system I should be fine.

That is why im asking so many questions And sorry to hijack the thread, I searched before I posted and could not find the info I was looking for. I figured it would be better to be all in one thread then 2 or 3.

 

As long as you are not going over speed bumps like that, I bet most any header would be fine. It is pretty common for people to lower c4's and have headers among other mods.

No offense, but you will have to be aware of your surroundings.

 

So really, if you cut the flange off the collector and used a band clamp, would that solve the clearance issues?

 

In the pics are hedman headers specific for C4. No air tubes. I ran the midamerican true duals(2.25in) to hooker aerochambers. very loud. too loud. never had clearance problems. I can measure clearance to pavement at flange if anyone would like.

 

If you did that.. would that band clamp seal properly?

 

Well, I bought the frikkin' headers and nobody has posted for a week.

Will I still be called a Hijacker for asking questions?

BTW, I installed from the bottom for my test fit with absolutely no issues.

My questions are about hooking up to my stock exhaust/Y pipe...

Before I cut anything, does the stock Y slip fit onto the street hook-ups?

Is there any bending involved or will the pipes line up OK?

Thanks,
JC

 

Yes they do, you just put a piece of aluminum foil where he seam is and it clamps down fine! Actually they come with a piece to do this but I used the foil

 

Thread jack!

If I did go with the band clamps going to a stock Y pipe would they not have to be a reducing coupling? Isn't the header collector 3" and the Y pipe 2.5"?

 

Going from memory, I believe this is correct.

3" to a 2.5" does not work Some Y pipes might even be 2.25. you need a reducer. Not sure if the headers come with it.

 

Mine were the elites but from what i understand they are the same exept for the flange and coating. I cut the stock y pipe and had the collectors welded in place.

 

this is a great picture. doesnt look like they hang down any further than the stock pipes except for the flange. I'm really thinking about using these on my 85 ZZ4 with AFR heads.
What y pipe did you use? I am almost thinking about going true dual all the way out.

 

I used a TPIS y pipe. It should be the same as your 85.
Here is the thread.

http://forums.corvetteforum.com/c4-t...te-videos.html

 

Easiest install ever. Pulled dipstick, plugs , wires and dropped front y tube. Bolted in with supplied bolts and used the existing where brackets connected. Went to Home Depot and bought 1/2" OD steel tube and cut my own new spacers using the length of the existing. MONEY! I sandblasted all the factory rust proofing off and then hit with propane torch and triple coated with 2000 degree flat black paint. Cut and modified y pipe as necessary. Y cuts were off so had a couple decent gaps to fill when welding but plenty strong. Hoping to get to track when it dries up and see how much better than 13.2 it will go