1 5/8" headers are fine for most applications. Anything above 600 rwhp and I would go 1 3/4". That's why I put 1 3/4" on mine.

 

I plan on staying withing the limits of the stock bottom end until way later on when I rebuild the motor after it gets a little tired. just out of curiosity I wonder what the exhaust manifolds on the gt500 look like?

 

They look like logs, seriously. The stock manifolds on the S197 GT at least resemble shorty headers, but those things on the GT500 - wow it's amazing that guys aren't getting 50hp just from installing long tubes on the thing!

 

I know there has been some back and forth on what size the primaries are on the OBX headers. Some say 1 3/4 and some say 1 5/8. So I decided to email the guy selling them on Ebay myself. He responded today and said they were 1 3/4 primaries. Here is the link to who I contacted.
Scott


http://cgi.ebay.com/ebaymotors/OBX-E...QQcmdZViewItem

 

I should be able to provide a accurate measurment tomorrow, will post after.

 

Hmm... I'm confused as far as the size of the primiaries. I'm N/A for now, atleast another year before I go s/c. What should I be looking for?

 

O.K. My OBX headers arrived today in fine shape
I got out my calipers & measured all 4 primaries on 1 header.
They are indeed 1 5/8" OD. There is some slight differences @ the bends, etc. But, they are NOT 1 3/4" primaries. The collector measures 2.5"
Now to get these installed,will post after they're in.

 

That is great news Larry. I trust your measure over the guys that sells them. 1 5/8 is better for us guys that are staying N/A but they still will flow much better than the stock logs. Are we going to get them put on for you this weekend????
Scott

 

Maybe I can't measure?

 

Faber,
If you are using a tape measure than it is tough to get it correct. Larry is using calipers so there is little room for mistakes. Even with your cams...I would be happy that they are 1 5/8. Better low end torque for us N/A guys!!!
Scott

 

no doubt.

 

I never had plans for L/T's but since this thread came out it looks like I'll be buying a pair for a spring mod.

 

i am seriously considering it also.

these look like a good deal. i have a ceramic coater that will do them for a good price too. hmmmm

 

I'll probably get them ceramic coated, too. But these will definitely be purchased this spring.

 

I want some too, let me know if anyone installs these with stock mufflers.

 

How big of a difference is having the L/T's ceramic coated? What are the pros of doing it and cons of not?

 

Ceramic coating can reduce underhood temperatures, while simultaneously helping to evacuate spent gasses from the motor by keeping the inside environment of the pipe extremely hot. The exhaust inside the cylander when evacuation begins is very hot. It usually exits into an environment that is not as hot and this causes the gasses to expand. This expansion slows the speed at which the exhaust gasses can flow out of the tubes and steals power. what kind of gains are you going to see by ceramic coating? I have not studied up on it, and I would bet it could be a significant amount depending on your setup. I didn't have mine coated but I am sure my car will make plenty of power just as well.

 

Back in the day (and I am sure still widely used) guys used to wrap thermal tape around their headers to achieve the same effect as ceramic coating does (though probbly not as efficiently) also if you want to get serious about exhaust scavenging you can find (or fabricate) a spot under the car where a vaccum exists an place the tip of the exhaust pipe in that spot to maximize the scavenging effect. Not entirely advisable on a passenger car since they sit in traffic often and the exhaust might kill ya...or make you

 

Wow this thread has really grown since I saw it last.

Faber,

Glad the LT's were everything I said they were. I was getting worried since I never did receive another PM from you. I guess I should've checked the thread sooner.


I've had mine on for about 3 months now, and still no issues. They still sound great, look great, and perform great. Like everyone else has said, quality at a great price is hard to come by these days. We have really found the "Diamond in the rough" for the LT's though.

 

Yes!

Great find Tragik!!!