Exhaust & Rear axle

Exhaust

The exhaust on this car took lots of time to build as it became complicated to route and build. Here are first some keywords:

Ford racing shorty headers that have Cobra flanges, 4 Mustang Cobra catalyzors , H pipe, 2 1/4" pipes from manifolds to mufflers. 2 1/2" pipes from mufflers to outlets. Outlets through orignal bumper guards. Mandrel bent bends.  Dynomax super turbo mufflers and stanless steel heat shields under the floor

The major problem was that everyone talks about nature and global warming today, so even if it would have been simpler , I wanted to keep both the EGR system and all 4 cats. The first 2 cats that come from a 200x Cobra, are mounted in front of the cross in the frame, and the main cats had to be placed where the mufflers normally are. So far OK, but where to place the mufflers ?. Actually there is only one place left ( for the size muffler I needed) and that is under the trunk floor. This was also OK, but then there was no room for the tank ( a chain reaction ) so I had to build a new tank that was narrower and a little deeper. Since the exhaust runs through holes in the cross in the frame, I have used some quick disconnect joints ( V-Clamps) , in case it have to be taken apart later. Due to that I have installed a Panhard rod on the rear axle, the exhaust had to pass over this rod on one side and under on the other side. Needless to say, there were no room for going over the rod on the side its going over, so I had to modify the floor in the trunk slightly, so there would be room.

These Thunderbirds were warm inside, and needless to say, having 4 cats under the floor do not help much, so I installed stainless steel shields over the cats, actually in the full length under the cabin, to overcome this unwanted heater.

The heat shields also provides good insulation for the emg brake and shifter cables, that would have been fried by the cats if there were no shields.

I'm using Hooker rolled tip outlets in the bumper guards, a great looking way of having large diameter oulets with a "stock" looking apparence.

The exhaust is supported 3 places, the front flanges, then after the rear cats, and then after the mufflers. This last mount were not easy, as there is not enough height to hang them, and since the Chrome ends had to come out perfectly in the center of the bumper guards, I had to make this special mount adjustable up / down and right / left. These mounts are pushing upwards with 2 rubber mounts on each side mounted in a  "A" form. This was the only way I saw this could be done. I guess some smaller mufflers would have helped. 

In this picture You can see the hanger after the cat's( on the H-Pipe ), so there are 4 rubber mounts, 2 sideways and 2 heightweise. There is a bracket screwed to the rails in the cross on each side that You not can see here. notice the V-band clamps ( click picture)

Rear axle

The original Thunderbird axle in 1955 were a Dana 44. Dana 44 has a 8.5" ring gear and should be able to handle 4-500 horsepower with the modification that I have done to it.

The donor car's rear end ratio were 3.27:1 , and I have installed a 3.31:1 gear set in it, on a brand new Auburn positraction differential carrier. Since tire size are close to donor car ( and Thunderbird ) outer diameter, I feel sure I will have gear shifts etc at proper levels.

The housing is narrowed 3/4 of and inch at each side to provide room for the 215-70-15 Bf Goodrich radial WWW tyres.

I guess You get an Idea how the narrowing was done , here in the garage with simple tools.

The new shorter axles comes from Strange Engineering.

Lesson learned:

Make sure panhard rod and sway bar is installed when making the exhaust, and make sure You can test for clerance under full suspension travel. The second time I made it I did these tests with only the main leaf spring installed, and some weight on the frame. It is a pussle to make the required clerance, around shocks, rods, bars and brake hoses.