During the install of my TiiCo conversion, I noticed that the exhaust fitting was going to be a little more challenging than that of the stock setup. I tried for maybe 1/2 an hour to get the muffler/cat to line up and bolt to the new exhaust header. After I failed miserably I asked for help for the Vanagon List. One response I got was from Kyle Wade. Here is the info that he gave me regarding the fitment of the muffler/cat.

First you remove the tailpipe (mine just unbolted, but I guess some have to be cut off). With my kit, on the mounting bracket on the passenger side of the van there were 2 bolts pointing toward the driver's side that held the rubber piece the exhaust bolts to. These bolts looked like they'd get in the way of the bracket, so I flipped them. Now the bolts are pointing toward the passenger side.

Then Kyle told me that some late model V'gons had a heat shield attached to the muffler. This needs to be removed (luckily my van didn't have this). Then drill the holes in the exhaust brackets as per the directions, but don't install them on the van yet. Next (it's much easier with a helper) you attach the cat/muffler to the TiiCo exhaust pipe with the OXS pointed up toward the air filter. After you have the cat/muffler bolted to the exhaust pipe, check the clearance between the muffler and the belts/bodywork. I had to bend a portion of the bodywork near the passenger side tow loop away from the muffler so it would clear (actually, even after I got it to fit, there was so little clearance that when I started the motor the end of the muffler body still hit the rear valence). Then you attach the passenger side exhaust bracket to the muffler and get it to slip over the ends of the bolts on the rubber mount.

The funny thing is that hole you drill in the driver's side bracket. The directions never say what it is for. It's for the strap that goes over the cat. Instead of hooking the strap in the original hooks, the post goes in that hole. You have to grind away a 1" or 2" section of the wider part of the strap so that it matches the width of the narrow part at the end that goes between the stock hooks. Once the passenger side is up and not interfering with the bodywork or the belts, then you install the driver's side bracket. I had to push the cat up about 1/2 an inch to get the mounting holes to line up. I installed the strap on the driver's side bracket before I installed it. I found that it would be darn near impossible to get the strap on after the bracket was installed.

In my case, there was no way to install the muffler without having it rattle against the bodywork. Needless to say, I got tired of that rattle after about 200 miles of driving the conversion (luckily it only rattled when going into reverse and when idling). I then searched the internet for viable solutions to my muffler problem. The solution that I found was a Magnaflow muffler. The part number is 10434. It has a 2" inlet/outlet and a 4" diameter body (as opposed to the stock muffler's 6" body). The tone of this muffler is much more noticeable than that of the stock muffler and it isn't as quiet. It should, however, give a little better performance. The gentleman who installed the new muffler was very forgiving about me hovering over his shoulder during the installation, and he did an excellent job fabricating a mount that bolted right to the TiiCo muffler bracket (as soon as I get some good daylight, I'll crawl underneath and take a picture of that as well).

Below are a couple pictures of the clearance between the new muffler and the bodywork.

Again, many thanks to Kyle Wade for his help!