Know the landed cost before you order
Prices include VAT. Shipping is charged separately and calculated at checkout for your destination. If no shipping option is shown, contact us for a quote before ordering.
Keep your GT350 rear mufflers when you fit Kooks headers
Join your Kooks long tube headers to the factory rear mufflers with these stainless GT350 X-pipe connections. Choose Competition Only or GREEN cats, both using 3" front pipework and 2-3/4" OEM rear outlets for the supported GT350 and GT350R.
SKUs: 11543100, 11543300
An X-pipe that keeps the factory rear system
The 304 stainless tubing is mandrel bent, and the rear connection retains the factory mufflers. The stock exhaust must be cut during installation. That is the fitting work that makes the retained rear system part of the header upgrade.
Choose the front catalyst arrangement
GREEN gives you a catted option suitable for forced induction. Competition Only supplies uncatted connections for competition use. Both options include the X-pipe and require Kooks long tube headers, which are a separate purchase.
Choose your configuration
| SKU | Configuration | Supplied arrangement | Fitting / engine conditions |
|---|---|---|---|
| 11543100 | Cat Type: Comp. Only; Include X-Pipe?: Yes | Competition Only connection assembly | Factory exhaust cut required; Uncatted; competition use |
| 11543300 | Cat Type: GREEN Cats; Include X-Pipe?: Yes | GREEN Cats connection assembly | Factory exhaust cut required |
Matching products
Pair these pipes with the GT350 stepped headers. To continue into a full 3" rear system, the GT350 rear section with mufflers is designed around the matching Kooks X-pipe and OEM connections.
Vehicle fitment
| Years | Vehicle / trim | Engine | Applicable SKU | Fitting conditions |
|---|---|---|---|---|
| 2015-2020 | Ford Mustang Shelby GT350R | 5.2L V8 | 11543100, 11543300 | Factory exhaust cut required |
| 2015-2020 | Ford Mustang Shelby GT350 | 5.2L V8 | 11543100, 11543300 | Factory exhaust cut required |
Intended use
11543100: Competition, off-road and track use only. Not for use on public roads.
The competition-use waiver applies to 11543100.
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 | 11543100, 11543300 |
| Applications | 2015-2020 Shelby GT350 / GT350R 5.2L V8 |
| Material | Mandrel-bent 304 stainless steel |
| Pipework | 3" X-pipe to 2-3/4" OEM rear outlets |
| Choices | Competition Only or GREEN |
| Retained parts | Factory rear mufflers |
| Installation | Factory exhaust must be cut |
| Required headers | Matching Kooks long tube headers; separate purchase |
Frequently asked questions
Does either option include an X-pipe?
Both options include the X-pipe.
Can I keep the factory mufflers?
Yes. The system retains them, with the required factory exhaust cut.
Are these direct replacements for pipes under the stock manifolds?
They require matching Kooks long tube headers.
