Installing Dual Dutras

Well this year I installed my Dutra's. I bought a pair from Doug a few years back and I have been using them to mock up the SC manifold. Since that has been figured out, I decided to install them.

I used this additional pieces for the install:

  • 4 - 2 1/8" J tubes from Summit Racing (3 were actually used)
  • 1 - 2 1/4" to 3" Flowmaster Y connector from Summit Racing
  • 1 - 3" to 2 1/2" Flowmaster Slip on Reducer from Summit Racing
  • 1 - 5' 2 1/2" exhaust pipe from the local NAPA
  • 1 - Flowtech Raptor Muffler with 2 1/2" offset inlet/centered outlet from the local Action Auto parts
  • 1 - Mini-stater from a 1995 Ram 1500 with 5.2 from Al's Lynnwood Truck Parts
  • 2 - 2 1/4" manifold flanges from A1's Muffler

Various clamps, hangers and adapters from the local auto parts stores (whoever had the cheapest prices).

Total cost, around $600 and 4.5 days of my time. Doing this yourself, gives you a new appreciation for those who actually do this for a living.

There has been some debate on the slantsix.org about the length of pipes, sizes of pipe, the routing of those pipes and other assorted stuff. For the record, how a '65 Dart is laid out pretty much dictates where the pipes need to run.

For example, to make it around the clutch linkage, the rear pipe pretty much needs to run over the starter and between the end of the pitman arm and the lower arm of the z-bar. This this will leave about 1/2" clearance between the linkage and a 1/4" clearance from the pitman arm. Slightly flattening the pipe opens this up to 1/2". The rear manifold needs to be clearanced for the electrical posts on the mini-starter. The flange also needs to be clearanced. I know SlantSixDan has posted alternatives for this on the site. But I choose to go this way.

The front pipe pretty much needs to run behind the dipstick and at an angle down towards the bell housing. Running in front of the dipstick brings the pipe too close to the steering box. The angle to clear the draglink and snake around the lower end of the bell housing took me most of a day to figure out. Running in front of the dipstick would have made that angle even harder.

The Y collector pretty much needs to end back by the transmission cross member. Remember, you are using straight pipe with as few bends as possible. This position makes everything easier to line up. I know, I tried several different placements.

Since I have a gas welder, there is no, way to hold the pipe with your fingers and zap it as aptly demonstrated by numerous how-to car shows. Sorry, mark, clamp, tack, and check is the order of the day. There is also a cut tack with hack saw step when things don't line up correctly. One good thing is that after 40 years, I finally figured out how to cut a straight line on pipe with a hack saw. Masking tape is your friend.

Now for a discussion on pipe sizes. My down pipes are 2 1/8" OD. They are not equal length, the rear pipe is shorter then the front pipe. The front pipe also has more bends in it then the rear pipe. theoretically this is bad, in reality, it most like doesn't make a bit of difference. The actual tail pipe is 2 1/2", it runs into a cheap turbo muffler knock off and dumps the exhaust out at the rear axle.

Some pundits, on this site, would say that I now have a loud car that has no low end torque that will eventually kill me from the exhaust gases leaking back into the car.

In reality, I have a car that has increased low end torque from 1000 rpms all the way up the scale. The exhaust is actually quieter then the previous 1 7/8" tail pipe with glass pack. The engine revs freer, performs better and is just nicer all way around.

The money and time were well spent.

Another thing, Doug, if you happen to read this, could you please make the outlet flanges parallel to the blocks center line. I am sure you have a good reason why you didn't, but it would make things so much easier.