Outdrives and Accessories - Bravo Extension Boxes

Single Bravo Sterndrive Extension Box Kit
Your Price:
$4,399.99

Single Bravo / Dual Ram Sterndrive Extension Box Kit

137-9631

Single Bravo / Dual Ram Sterndrive Extension Box Kit

The Mayfair standoff box kit is the most advanced, easy to install, state of the art system on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear. Mayfairs’ torsional driveshaft and the Mercruiser high performance coupler are designed to absorb shock to the Bravo outdrive. All Mayfair extension boxes are manufactured from356 T-6 cast aluminum, CNC machined for accuracy, and then hard anodized for supreme corrosion resistance.

This kit includes:

  • Extension Standoff Boxes
  • Backing Plates
  • Rear Engine Mount Pads
  • Extended Bravo Drive Lines
  • Extension Box Mounting Hardware
  • Dual Cylinder Mayfair Add-On Hydraulic Steering Kit

NOTE: When running a standoff box, you must use a twin ram full power steering system.


Single Bravo Sterndrive Extension Box Kit
Your Price:
$2,199.99

Single Bravo Sterndrive Extension Box Kit

137-9630

Single Bravo Sterndrive Extension Box Kit

The Mayfair standoff box kit is the most advanced, easy to install, state of the art system on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear. Mayfairs’ torsional driveshaft and the Mercruiser high performance coupler are designed to absorb shock to the Bravo outdrive. All Mayfair extension boxes are manufactured from 356 T-6 cast aluminum, CNC machined for accuracy, and then hard anodized for supreme corrosion resistance.

This kit includes:

  • Extension Standoff Box
  • Backing Plate
  • Rear Engine Mount Pads
  • Extended Bravo Drive Line
  • Extension Box Mounting Hardware

NOTE: When running a standoff box, you must use a twin ram full power steering system. This Kit does NOT include Steering.


U-Joint Extension Box Drive Shaft
Starting From:
$706.50

This Part has options, please click the button below to order.

U-Joint Extension Box Drive Shaft

421-DS + Option(s)

U-Joint Extension Box Drive Shaft


Dual (Twin) Bravo Sterndrive Extension Box Kit
Your Price:
$7,599.99

Dual (Twin) Bravo / Dual Ram Sterndrive Extension Box Kit

137-9633

Dual (Twin) Bravo / Dual Ram Sterndrive Extension Box Kit

The Mayfair standoff box kit is the most advanced, easy to install, state of the art system on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear. Mayfairs’ torsional driveshaft and the Mercruiser high performance coupler are designed to absorb shock to the Bravo outdrive. All Mayfair extension boxes are manufactured from 356 T-6 cast aluminum, CNC machined for accuracy, and then hard anodized for supreme corrosion resistance.

This kit includes:

  • Extension Standoff Boxes
  • Backing Plates
  • Rear Engine Mount Pads
  • Extended Bravo Drive Linse
  • Extension Box Mounting Hardware
  • Dual Cylinder Mayfair Add-On Hydraulic Steering Kit

NOTE: When running a standoff box, you must use a twin ram full power steering system.


Dual Engine (Twin) Bravo Sterndrive Extension Box Kit
Your Price:
$4,299.99

Dual Engine (Twin) Bravo Sterndrive Extension Box Kit

137-9632

Dual Engine (Twin) Bravo Sterndrive Extension Box Kit

The Mayfair standoff box kit is the most advanced, easy to install, state of the art system on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear. Mayfairs’ torsional driveshaft and the Mercruiser high performance coupler are designed to absorb shock to the Bravo outdrive. All Mayfair extension boxes are manufactured from356 T-6 cast aluminum, CNC machined for accuracy, and then hard anodized for supreme corrosion resistance.

This kit includes:

  • Extension Standoff Box
  • Backing Plate
  • Rear Engine Mount Pads
  • Extended Bravo Drive Line
  • Extension Box Mounting Hardware

NOTE: When running a standoff box, you must use a twin ram full power steering system. This kit does NOT include Steering.


IMCO Standard Height Extension Box Only
Your Price:
$1,799.99

Standard Height Extension Box Only

421-TEB

IMCO Standard Height Extension Box Only

This is the most advanced, easy to install, state of the art standard box on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear, and on and off throttle operations. Inferior designed competitor's boxes use a drive shaft that is solid mounted to the flywheel, doing away with your coupler. Their units literally hammer the internal components in your drive, which rapidly accelerates failure.

IMCO's torsional driveshaft and the stock MerCruiser rubber coupler are designed to absorb shock resulting from extreme high performance applications and rough water conditions.

356 T-6 cast aluminum transom motor mount brackets available for both neutral and 3"lift extension boxes.

Lightweight super strong cast 356 T-6 aluminum extension boxes, available in 12" neutral set-back or 12" set-back with 3" lift.

356 T-6 aluminum side mount steering brackets allows ample mounting clearance for optimum K-Plane placement - clears most exhaust ports, swim brackets, etc. - keeps rams on pivot center line.

IMCO Standard Height Extension Box Only

Standard Height Extension Box with Torsional Drive Line Neutral
Your Price:
$2,849.99

Standard Height Extension Box with Torsional Drive Line Neutral

421-TEBK

IMCO Standard Height Extension Box with Torsional Drive Line Neutral

This is the most advanced, easy to install, state of the art standard box on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear, and on and off throttle operations. Inferior designed competitor's boxes use a drive shaft that is solid mounted to the flywheel, doing away with your coupler. Their units literally hammer the internal components in your drive, which rapidly accelerates failure.

IMCO's torsional driveshaft and the stock MerCruiser rubber coupler are designed to absorb shock resulting from extreme high performance applications and rough water conditions.

356 T-6 cast aluminum transom motor mount brackets available for both neutral and 3"lift extension boxes.

Lightweight super strong cast 356 T-6 aluminum extension boxes, available in 12" neutral set-back or 12" set-back with 3" lift.

356 T-6 aluminum side mount steering brackets allows ample mounting clearance for optimum K-Plane placement - clears most exhaust ports, swim brackets, etc. - keeps rams on pivot center line.

Kit includes Stand off Box, Torsional Drive Line and Neutral Mount Bracket. Steering Arms sold separately.


Extension Box with Torsional Drive Line and 3" Raised Inner Transom Assembly
Your Price:
$2,849.97

Extension Box with Torsional Drive Line and 3" Raised Inner Transom Assembly

421-TEBK1

IMCO 3" Higher Extension Box with Torsional Drive Line and 3" Raised Inner Transom Assembly

    Kit includes:
  • Stand off Box
  • Torsional Drive Line
  • 3" Raised Bracket

This is the most advanced, easy to install, state of the art standard box on the market today. The torsional drive shaft helps cushion the shock to the outdrive when shifting in and out of gear, and on and off throttle operations. Inferior designed competitor's boxes use a drive shaft that is solid mounted to the flywheel, doing away with your coupler. Their units literally hammer the internal components in your drive, which rapidly accelerates failure.

IMCO's torsional driveshaft and the stock MerCruiser rubber coupler are designed to absorb shock resulting from extreme high performance applications and rough water conditions.

356 T-6 cast aluminum transom motor mount brackets available for both neutral and 3"lift extension boxes.

Lightweight super strong cast 356 T-6 aluminum extension boxes, available in 12" neutral set-back or 12" set-back with 3" lift.

356 T-6 aluminum side mount steering brackets allows ample mounting clearance for optimum K-Plane placement - clears most exhaust ports, swim brackets, etc. - keeps rams on pivot center line.

Note: Steering Arms sold separately.


Ram Bracket Left
Your Price:
$459.99

Ram Bracket Left

421-WP-8-L

Ram Bracket Left


Ram Bracket Right
Your Price:
$489.00

Ram Bracket Right

421-WP-8-R

Ram Bracket Right


Offshore Race Upgrade Kit for Mayfair Extension Boxes
Your Price:
$1,999.99

Offshore Race Upgrade Kit for Mayfair Extension Boxes

137-9634

Offshore Race Upgrade Kit for Mayfair Extension Boxes

The upgrade kit is recommended only for all out race applications with high horsepower engines.

This kit will come with:

  • a billet bearing carrier
  • a power take off for the crankshaft
  • a splined flange to connect the Bravo drive and driveshaft assembly together.

NOTE: This is not recommended for pleasure boats.


Splined Coupler
Your Price:
$459.99

Splined Coupler

137-9647

Splined Coupler