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Choose the crossover for your supercharged Shelby
Complete your GT500 header installation with the crossover and catalyst arrangement you want. These Kooks connections offer X-pipe or H-pipe layouts, in GREEN-catted or uncatted Competition Only form. Both layouts join the factory-style rear exhaust through 2-3/4" outlets.
SKUs: 11423100, 11423300, 11423400, 11423600
Four real configurations
Choose 11423100 for an uncatted X-pipe or 11423300 for a GREEN X-pipe. The H-pipe choices are uncatted 11423400 and GREEN 11423600. The GREEN cats use a 400-cell substrate and suit forced induction.
Fit the complete front system
The 3" pipework uses ball-and-socket connections to Kooks long tube headers. Front clamps are included, while the rear joint reuses the original OEM clamps, purchased separately if replacements are needed.
Choose the sound you enjoy
An X-pipe typically gives a smoother, higher-pitched exhaust note. An H-pipe brings the deeper, classic muscle-car sound. Your choice of cats and rear mufflers also shapes what you hear from your GT500.
Choose your configuration
| SKU | Configuration | Supplied arrangement | Fitting / engine conditions |
|---|---|---|---|
| 11423100 | Cat Type: Comp. Only; Crossover Type: X Pipe | Competition Only X-pipe; front clamps included; rear OEM clamps reused. | Uncatted; competition use |
| 11423300 | Cat Type: GREEN Cats; Crossover Type: X Pipe | GREEN X-pipe, 400-cell cats suitable for forced induction; front clamps included; rear OEM clamps reused. | Match the vehicle and engine rows below |
| 11423400 | Cat Type: Comp. Only; Crossover Type: H Pipe | Competition Only H-pipe; front clamps included; rear OEM clamps reused. | Uncatted; competition use |
| 11423600 | Cat Type: GREEN Cats; Crossover Type: H Pipe | GREEN H-pipe, 400-cell cats suitable for forced induction; front clamps included; rear OEM clamps reused. | Match the vehicle and engine rows below |
Matching products
The 2011-2014 GT500 headers have 3-inch collectors for these crossovers, within the listed 5.4/5.8 GT500 years.
Vehicle fitment
| Years | Vehicle / trim | Engine | Applicable SKU | Fitting conditions |
|---|---|---|---|---|
| 2011-2012 | Ford Mustang Shelby GT500 | 5.4L V8 | 11423100, 11423300, 11423400, 11423600 | |
| 2013-2014 | Ford Mustang Shelby GT500 | 5.8L V8 | 11423100, 11423300, 11423400, 11423600 |
Intended use
11423100, 11423400: Competition, off-road and track use only. Not for use on public roads.
The competition-use waiver applies to 11423100, 11423400.
Ordering and delivery
Estimated lead time is 4-6 weeks. Delivery may be faster depending on stock levels. Shipping is charged separately.
Technical specifications
| Specification | Details |
|---|---|
| SKUs | 11423100, 11423300, 11423400, 11423600 |
| Application | 2011-2012 GT500 5.4L; 2013-2014 GT500 5.8L |
| Material | 16-gauge 304 stainless steel |
| Front / OEM outlet | 3" / 2-3/4" |
| Crossovers | X-pipe or H-pipe |
| GREEN cats | 400-cell; suitable for forced induction |
| Clamps | Front supplied; rear OEM clamps not included |
Frequently asked questions
Do both layouts fit the factory-style rear exhaust?
Yes. Both have the 2-3/4" OEM rear outlet for the GT500 applications.
Does choosing the H-pipe change the header requirement?
Both layouts require matching Kooks long tube headers.
