Dutra Duals

This project started in the mid-1980's when the exhaust manifold cracked on my 1965 Plymouth Barracuda. Since I was already planning on making some performance upgrades, headers seemed a natural fit. I ordered a set of headers from Clifford Research (now Clifford Performance) to fit Mopar narrow A-bodies. To make them last longer, I had them aluminum coated. However after over 10 years of service, they rusted out in spite of the aluminizing. Probably the header wrap I put on them to keep the heat down in the engine compartment didn't help either.

After much deliberation and research, I decided to replace them with a set of Dutra Duals . I don't plan on selling my car so I wanted to avoid the problem of headers rusting out or manifolds cracking. The following is a chronicle of this adventure.

For more information, visit: Doug's Slant Six Dutra Duals.

 

Slant Six with AFB

My engine with the old leaking headers and Carter AFB 9625 4bbl carburetor.
Rusted Out Headers

This huge hole made the car too loud to drive. Notice the wear on the other set of headers from rubbing on the steering linkage.
Starter Solenoid Interference

I need to relocate my starter solenoid! Luckily, new rear manifold flange easily clears the original starter so I don't need to buy the newer compact starter. I just need to find a new home for the solenoid.
Exhaust Manifold Leak

When I got the exhaust pipes hooked up I discovered I had an huge exhaust leak that I could not stop at the muffler shop. It was a loud drive home. The above picture shows that the bottom of cylinder #1's port is hung up on the engine boss.
Exhaust Manifold Flanges

This is what the manifold's flange looked like when I removed it. So much for trying to save the manifold gasket.
Mounted Dutra Duals

The new manifolds make the engine compartment look a lot cleaner. The carb seemed to be running a lot leaner with the new exhaust arrangement. Enriching the primary circuit made a big improvement in the drivability. Yes, the new pipes are T304 SS.
Solenoid Mount

This is new home for the starter solenoid. I made up a mounting plate from aluminum to solidly mount the solenoid to the intake manifold. All I had to do to the solenoid was flatten its bracket as it was curved to match the diameter of the starter.
Slant Six Heat Plate

After trying to eliminate the off-idle bog I was having first with the AFB and later to a lesser extent with the Quadrajet, I added heat to intake manifold. This heater completely eliminated the bog and I highly recommend keeping the manifold heat control valve in good working order, especially when you are using a larger carburetor.