OK, here are some closeups. All these bends were on a single chunk of pipe I had made up as a temp airpipe when I redid my turbocharger installation on my pickup a few years ago. It was setting in my scrap pile. You could have a piece of pipe bent up with the necessary bends for a few bucks, then you just cut them apart with a sawsall or metal chopsaw. You could also buy pre-bent elbows at an auto parts store.
The first pic is of the manifold. My manifold outlet had a 3/4" thick cast spacer(seen between 1 and 2 on the measuring tape) between the manifold outlet and the cast iron long elbow that protrudes straight out from the manifold. The stock muffler sets on this cast elbow with a 4 bolt flange. The bolt spacing on my spacer is 3" with about a 1 3/4" center hole. I found a 2 hole diamond flange that was exactly the same size at a muffler shop for about $5. Most exhaust shops have a wall full of these on pegs. Just take the spacer or elbow along with you to size the proper one. The flange had about a 2 1/8" center hole which was perfect for the 2" pipe to fit into for welding. I cut the elbow to a length that placed the muffler in the middle of the space between the hood and the loader arm. Looking at it now, you may be able to find or make a 4 bolt flange to weld on the other end of that first elbow to which you could bolt the stock muffler without having to cut/modify the bottom end of the muffler like I did, but instead bolt it together.
I added a support strut from the pipe down to the loader support arm. The muffler weight hanging off the elbow and only being supported at the end of the outpet pipe didn't look that good to me once I thought about engine vibration. This strut supports that weight. The muffler material is also very thin, and due to the number of times I had bent mine, it was cracked a good ways around and required some very carefull welding to fill the holes. The bolt at the bottom allows me to remove the exhaust pipe as one piece. Due to the condition of mine, if I could have found a replacement easilly/quickly, I would have replaced it. If it gives me any more trouble, I will replace it.
The downpipe bracket is just a little scrap of angle that sets over an existing drilled and tapped hole in the tractor side frame.
All the tube bends were 90 degrees. As you can see in this next photo, the pipe angles forward slightly to reach my end anchor point. IF I was having this done, I would probably spec an 80 degree bend. If you use the 4 bolt flange on the end of the first elbow to bolt the muffler to, then the muffler will be about 1 1/2-2" further forward, and a 90 degree bend would probably get the pipe outlet to about the same point down in front of the battery.
Like I said, I am going to add a difuser to mine that runs across under the front tractor frame about like in the next pic. This difuser will have small holes in the sides and along the front that will have a total surface area equal to that of the 2" pipe.
If you could get a 2 and 4 bolt flange and that first elbow fit in the right orientation, someone else might be able to weld them together for you. Then you could bolt the muffler to that 4 bolt flange and cut off the upper pipe. Once you did this, you would know exactly what bends you need in a single pipe to get down to the spot alongside the front frame. You could even have a second bend to angle the pipe across the front like where I am going to place my difuser. To the end of that pipe you could attach your spark arrestor.
Good Luck.
