In the previous months, we've begun to show you the finer points to swapping a Three-Valve 4.6L Mustang powerplant into the Fox-body chassis. Luckily, the Mustang aftermarket is onto the trend, and many of the needed parts for the conversion are readily available. One of the hardest parts we ran into (so far) is the exhaust-namely the headers. Being that the 4.6L is significantly wider than the old 5.0L, real estate for headers is at a minimum.
When we began to plan this phase of the project, we did a lot of research and looked into both long- and short-tube headers-we even tried the factory cast manifolds. In the end, we went with a hybrid header of sorts. American Racing Headers (ARH) of Amityville, New York, fabricated a set of Two-Valve mod motor headers with Three-Valve flanges so it would bolt up to our FRPP Hot Rod crate engine. The guys at ARH only tack-welded the primary tubes to the flanges and collectors so modifications could be made to ensure correct fitment.
For our installation, we headed back to Coastal Chassis Dyno in Tampa, Florida. With loads of experience in fabricating custom turbo kits, Sam Lippencott and Horacio Ramos are veterans when it comes to customized exhaust systems.
We knew that going into this part of the project could require a significant amount of time and fabrication to get it right, but we also knew it was something we only wanted to do once. With our ARH headers in hand, we began test-fitting the tubes, as well as making the necessary modifications for a perfect fit. After a few hours in the shop, we had pipes on the engine and were ready to take on the next step in this build.