The Borla CrateMuffler is purpose-built to optimize the sound and power of crate and custom-built engines. This ATAK muffler is tuned for the Chevrolet Big Block 396, 402 and 427 CID V8 engine family and is directional, with the outlet end identified by the mounting bracket welded to the end cap; the tuned design delivers the aggressive, high-output ATAK sound and dramatically reduces or eliminates drone on cataloged applications. It is built from premium T-304 stainless steel, superior to T-400 series such as 409, with CNC-precision manufacturing for an accurate fit. Borla exhaust is handmade in the USA and backed by the Borla Million-Mile Warranty.
Specifications:
- System type: directional CrateMuffler, tuned per engine family
- Engine application: BBC 396/402/427
- Sound level: ATAK
- Inlet: 2.5 inch offset
- Outlet: 2.5 inch center
- Body: 4.35in x 9.10in oval
- Body length: 14 inch
- Overall length: 19 inch
- Material: T-304 austenitic stainless steel
- Construction: 100 percent welded
- Made in the USA
- Part number: 400852
FAQ
What engine is the Borla 400852 CrateMuffler tuned for?
It is tuned for the Chevrolet Big Block 396, 402 and 427 CID V8 engine family. Borla CrateMufflers are directional and engine-specific, so the tuned internals deliver a custom sound and reduce or eliminate drone on cataloged applications. The outlet end is identified by the mounting bracket welded to the end cap.
What sound level does it produce?
It produces the aggressive, high-output ATAK sound.
Is this a 50-state emissions legal or street legal part?
This is a universal weld-in exhaust component, not a complete vehicle-specific system. Emissions compliance and street legality depend on the complete exhaust system and the specific vehicle it is installed on, so a universal part sold on its own carries no standalone emissions certification. Confirm the requirements for your state and application before installing.
What are the dimensions and how does it mount?
It has a 2.5 inch offset inlet and 2.5 inch center outlet, a 4.35in x 9.10in oval body, 14 inch body length and 19 inch overall length. It is directional, so install it with the bracketed outlet end facing the tailpipe, and it is fully welded from T-304 stainless steel.
Where is it made and is it warrantied?
It is built in the USA from T-304 austenitic stainless steel and is backed by the Borla Million-Mile Warranty.
