A few things to consider when sourcing a kit:

• The beaver tail was originally installed to help keep snow in the tunnel and thus keep the motor running cool. When sourcing a kit you want to see if they specifically list that the kit does not create any issues with the sled overheating.
• You need it made of heavy material that is going to be strong enough to last and mount strong enough that you’ll be able to lift the sled up by the bumper with a tunnel full of snow.
• You want something that's going to look good.
• You may want to use the 1+1 seat on your sled so the kit should not interfere with it.

When searching for something that would meet all of these needs I ran across a kit for sale on eBay by www.skidooextreme.com. This kit ("Complete full 2005 style kit" found at http://www.skidooextreme.com/id1.html) not only had a good-looking tunnel extension but also includes the stock plastic pieces that from a 2005 snowmobile. This kit includes moving the tail light from the back of the seat to the tunnel and adds a rack that covers the tunnel extension. Also, with this kit they specifically listed that they have not run into any heating or strength issues. Chalk up one more eBay purchase for me.

The Fed Ex guy showed up a few days later with a large box that included the following:

• Tunnel extension
• Tunnel rack and tail light housing
• 2004 heavy duty bumper and end caps
• Plastic piece that covers off the back of the seat
• More then a few fasteners
• Instructions

There are four parts to this install and the instructions were well laid out. I found the pictures rather dark to follow but everything became clear once I started working on the sled.

The start of the project with the stock beaver tail

Step1: Removing the beaver tail

This is fairly straight forward. You only have four bolts to undo and the stock beaver tail is removed from the sled.

Step 2: Remove the seat mounting hardware

 You need to remove the metal bracket that's used to hold the rear of the seat to the sled. To access it, you remove the trunk and seat from the sled which is done by removing four screws and two nuts. Once those pieces are out of the way, the seat mounting bracket is removed by removing the 12 rivets that hold it, and the beaver tail mounting brackets to the tunnel. I removed them using a 3/8" drill bit and drilling the top of the rivet heads of and then knocking the rivets through the tunnel with a hammer and punch.

Once you remove the beaver tail you realize how short the tunnel is on this sled.

Step 3: Attach the seat hardware and tunnel extension
The instructions that came in the kit mention that the next steps are easier if you remove the tank from the snowmobile. Since that‘s a fairly major task on the Rev, I elected to leave mine on the sled and work around it. If you want, you can remove the tank to give you unrestricted access to all the rivets you need to install.

You will need to cut the eyelets off the beaver tail mounting brackets as they are reused.

You install the tunnel extension onto the sled and use c-clamps to pull it down into place and to hold it there while you are pulling the rivets. Place the seat mounting bracket on top of the tunnel extension and then put the modified beaver tail mounting brackets under the tunnel and then rivet it all together. There are a pair of rivets that are under the gas tank that are impossible to pull if you've left the gas tank installed. Instead I used a few small stainless bolts with washers and nylock nuts in lieu of rivets for these two. Once the tunnel extension attached I placed a small bead of silicon to the inside of the tunnel between the tunnel and the extension.

The new tunnel extension installed.

Once the new tunnel extension is installed I noticed that the original tunnel looked quite dull compared to the new tunnel extension. I pulled out the Mothers Powerball metal polisher (http://www.mothers.com/products/productcatalog/power_prod.html) and did a quick job of polishing the tunnel and the extension. This product does an amazing job in a short amount of time, and I highly recommend it to anyone who needs to polish aluminium.

Step 4: Install the new plastic pieces, bumper and snow flap
Once the new tunnel extension is installed it's time to get the plastic pieces on the sled. First remove the tail light from the original trunk and install it in the new tunnel rack. First piece to bolt up is the new trunk which is held on by two screws and two bolts. The next part proved to be a little tricky as I found the tunnel rack didn't slide under the new trunk.  I marked the trunk, removed it and shaved 1/16" off of parts of the trunk so the rack could slide under it. After that was accomplished it all fit together perfectly.

After a bit of careful trimming it all fit together perfectly.

Next was to install the snow flap. I ran into another glitch where my rivet guns didn't have a long enough nose on them to be able to pull the rivets that were included in the kit. I turned again to some small stainless steel bolts with some washers and nylock nuts to do the job. Last step of the job was to install the new heavy duty bumper which is held on by the six bolts included in the kit.

All in all I thoroughly enjoyed working with this kit. The parts fit together really well and the instructions were easy to follow. If you're considering updating your '03 Rev to a more modern look I would most definitely recommend looking into this kit.

Now that's a good looking ride!