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.
![]() My engine with the old leaking headers and Carter AFB 9625 4bbl carburetor. |
![]() 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. |
![]() 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. |
![]() 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. |
![]() This is what the manifold's flange looked like when I removed it. So much for trying to save the manifold gasket. |
![]() 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. |
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. |
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. |