Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums - Camaro5.com - View Single Post - So..what exactly is the difference between Kooks and Knockoffs? (in pictures)

MarylandSpeed · 01-09-2011, 01:01 AM

Been sitting on this for a while..trying to decide if I wanted to post them. At the end of the day, I figured it was best to let the customers see the pictures and decide for themselves since most will never get a chance to see both in person.

What we have here is a picture of Kooks headers next to...well..we will just say a popular brand of ebay headers. Both are new..fresh out the box. We procured a set of these since members wanted to see proof.

No measuring tape needed here..apple does not fall from the tree..

So now that we have established that they are basically the same design..what are the differences?

Well the big difference is in fit and finish. Many of the pipes where the ebay headers go into the flange are ovaled and less than round. Trying to weld oval pipe to a round flange creates issues.

This is what a Kooks header looks like inside the flange.

At first this does not look like a big deal. (Kooks on the right)

However..if you want an actual 1 7/8" header...then this could be an issue. This is caused because of the benders they are using ovaling the pipe. When you run your hands around the pipe, you can feel how it is ovaled.

Here is a measurement of inside one of those flanges..barely 1.7"

Another picture of Kooks flange

This pictures shows an ebay header primary. You can see the crease in the pipe from where the bender took it out of round.

Here is a Kooks header. The pipe looks much more round. running your hand around, you can feel the difference between the two. The Kooks pipe itself is marked up because it is not polished. Those are a normal part of the bending process.

Here is the Kooks header merge collector next to their standard collector.

We had an issue with this collector. The weld slag was so thick we had issues getting the flange to slide past it.

Inside the two collectors. Not much going on here. The ebay header's merge spike is not as semetrical and kind of ugly.

Here is a picture of the two flanges. For some reason, the ebay header has a misxure of oval and round bolt holes, and even the round bolt holes are bigger than Kooks. This can create issues matching the ports togethor. The ebay header is using a 1/2" flange, which is thicker than the 3/8" flange the Kooks, SW, and pretty much everyone else uses. I think this comes from the cheaper ebay headers having a repuation for warped flanges back in the day. Kinda like an over reaction to prevent it in the future. The industry standard 3/8" flange is best for most applications where you are using quality materials because it provides a middle ground bettwen being really think and allowing the bolts to sink into the head more for a better seal.

New here is something curious. Despite the headers being the exact same length, the Kooks mid pipes are longer. I am not sure why the ebay header has shorter mid pipes? One issue I could see is this will mean that the mid mipe will not butt up to the catback like it should, and would leave the factory band clamp to have to seal the gap.

The Kooks mids are the taller ones with the tags on the bottom.

01-09-2011, 01:01 AM	#1
MarylandSpeed Account Suspended Drives: 2012 ZL1 & 2010 2SS/RS Join Date: Jul 2009 Location: Maryland Posts: 3,378	So..what exactly is the difference between Kooks and Knockoffs? (in pictures) Been sitting on this for a while..trying to decide if I wanted to post them. At the end of the day, I figured it was best to let the customers see the pictures and decide for themselves since most will never get a chance to see both in person. What we have here is a picture of Kooks headers next to...well..we will just say a popular brand of ebay headers. Both are new..fresh out the box. We procured a set of these since members wanted to see proof. No measuring tape needed here..apple does not fall from the tree.. So now that we have established that they are basically the same design..what are the differences? Well the big difference is in fit and finish. Many of the pipes where the ebay headers go into the flange are ovaled and less than round. Trying to weld oval pipe to a round flange creates issues. This is what a Kooks header looks like inside the flange. At first this does not look like a big deal. (Kooks on the right) However..if you want an actual 1 7/8" header...then this could be an issue. This is caused because of the benders they are using ovaling the pipe. When you run your hands around the pipe, you can feel how it is ovaled. Here is a measurement of inside one of those flanges..barely 1.7" Another picture of Kooks flange This pictures shows an ebay header primary. You can see the crease in the pipe from where the bender took it out of round. Here is a Kooks header. The pipe looks much more round. running your hand around, you can feel the difference between the two. The Kooks pipe itself is marked up because it is not polished. Those are a normal part of the bending process. Here is the Kooks header merge collector next to their standard collector. We had an issue with this collector. The weld slag was so thick we had issues getting the flange to slide past it. Inside the two collectors. Not much going on here. The ebay header's merge spike is not as semetrical and kind of ugly. Here is a picture of the two flanges. For some reason, the ebay header has a misxure of oval and round bolt holes, and even the round bolt holes are bigger than Kooks. This can create issues matching the ports togethor. The ebay header is using a 1/2" flange, which is thicker than the 3/8" flange the Kooks, SW, and pretty much everyone else uses. I think this comes from the cheaper ebay headers having a repuation for warped flanges back in the day. Kinda like an over reaction to prevent it in the future. The industry standard 3/8" flange is best for most applications where you are using quality materials because it provides a middle ground bettwen being really think and allowing the bolts to sink into the head more for a better seal. New here is something curious. Despite the headers being the exact same length, the Kooks mid pipes are longer. I am not sure why the ebay header has shorter mid pipes? One issue I could see is this will mean that the mid mipe will not butt up to the catback like it should, and would leave the factory band clamp to have to seal the gap. The Kooks mids are the taller ones with the tags on the bottom. Last edited by MarylandSpeed; 08-01-2011 at 04:32 AM.