When you’ve been in the header-making business since 1962, as Kooks Custom Headers has been, you learn a thing or two about how to bend pipe and weld steel. So when it came time for Associate Editor Greg “Donut” Acosta to select a set of headers for his awesome Boss Hog engine project, he knew exactly who to call, especially since he wanted an interesting custom touch on the headers he needed. These headers, Kooks PN 4025S, are designed to be used with the Air Flow Research cylinder heads that top off Boss Hog’s shortblock. They consist of 1-7/8-inch primary tubes and three-inch slip-on collectors and specifically fit the ’94-’95 early SN-95 chassis. They are built using 304 stainless steel, as are all of Kooks’ header designs, which make these pieces perfect for the application. 304 stainless is a high-grade alloy, renowned for its ability to resist cracking and flaking unlike mild steel. Stainless steel by definition is constructed using a minimum of 11-percent chromium content by mass, and 304 stainless is the most widely used and versatile of all stainless types of steel. Its excellent forming and welding characteristics make it ideal for use in header designs, while the corrosion resistance is considered excellent, making them most likely the last set of headers you’ll need to buy for a long time. The pair of AEM 4-channel wideband O2 controllers and AQ-1 datalogger system Acosta is using in Project Nutjob allows for the input from eight individual oxygen sensors, so of course they all needed to be utilized—Donut spec’d them out to be installed at the top of each tube, near the exhaust port on the cylinder head. His mind is constantly working on one science project or another; as he has a knack for analyzing information and this portion of the advanced project is right up his alley.
Kooks is well-known for their high-quality collectors, and this pair is a shining example of the breed. The spike in the center is designed to help guide the airflow towards the center of the collector, thus increasing velocity and scavenging ability.
These XX Carbon gaskets are supplied with the headers are made from a proprietary carbon material, and can withstand exhaust temperatures over 2,000- degrees Fahrenheit. Their unique design offers superior sealing ability and works great on power-adder engines.
The eight (!) oxygen sensors that Donut is using with his AEM wideband screw into these stainless steel bungs, AEM PN 30-2003. Since the headers are also constructed from stainless steel material, there is no chance of cracking around the welds due to dissimilar expansion rates.
The fact that Donut was able to find these on the shelf at Kooks was perfect for the timing of the project, and the Kooks team jumped at the opportunity to be involved. “With the eight bungs in the tops of the primary tubes, we were able to eliminate the two in the collectors, because ten sensors would just be overkill,” he laughed. He continued on, explaining that there was a longevity reason to choose these as well. “Most importantly we wanted stainless headers to go with the stainless bungs. This way we wouldn’t have any issues with dissimilar metals expanding and contracting at different rates as the headers heated and cooled, also help- ing to reduce the chance of premature cracking where the bungs were installed. Kooks offered stainless, 1-7/8-inch pri- mary, spread-pattern flange headers specifically for the ’94-’95 GT. No one else even had that combination as a shelf- stock part number, and it was great to be able to find headers without having to have a true on-the-car set made, which would have been cost-prohibitive for this project.” But before you think these are just tubes welded together, think again. As George Kook Jr., explained to us a number of years ago when we toured Kooks’ old location, “It’s all engineering. There’s a lot more to hot-rod building, and header building in specific, than just welding up a bunch of tubing. Everything has to be considered when creating headers for a car—from fitment to sound to everything else.” And on this beautiful set of headers, it was.
Kooks Custom Headers
http://www.kookscustomheaders.com
866-586-KOOK
