The 4.6-liter engine replaced the Ascot series of Ford V8s. The 221 cubic inch V8 that debuted in the 1962 Ford Fairlane could eventually be available in a variety of familiar-sounding sizes (289, 302, and 351) and drive anything from Falcons to F-350s. Despite its adaptability, it has outlived its usefulness.
Ford knew it had to move on, and the 4.6 was a clear indication of that. Ford's 4.6 litre V8 was the first of its kind, dubbed "Modular Engines" at the time. The term "modular" was used to describe the production technique, not the transferability of components, when defining the 4.6, 5.4, and 6.8 litre V8s. Here is full guide about Ford 4.6 Firing Order https://nerdycar.com/firing-order-for-ford-4-6/