So now with the "why" question answered, the "how" lurks ominously. If you've got a wider '67 and up car, it's an easier swap, but our early cars are narrower and shorter, needing a lot more trimming and shoe-horning to squeeze a 4.6L or 5.4L in between the towers. So much for the reversible restomod; the physical size of the new design is simply put "a square peg in a round hole" in an early Mustang. Before you think we're trying to talk anybody out of this swap, think again.
It's very cool and visually stunning when you open the hood, and thanks to awesome aftermarket support, the Four-Valve swap is accessible. Shaving a little off the shock towers to fit a larger engine into a Mustang is nothing new at all (can you say Boss 429?). Besides, more and more options are surfacing every day in regards to fuel delivery, electronic engine management systems, and fitment, or as we'll refer to them, the "big three" challenges.
Read on as we'll show you some great options for the big three challenges of installing a DOHC 4.6L modular EFI engine into a classic car, and some new and interesting alternatives for customizing and improving on the decades-old engineering inherent in our wonderful, but aged cars via our exploration into building a '66 Mustang with a dual fuel capable 4.6L Four-Valve drivetrain. The project, dubbed LPGT (Liquid Propane GT) is something we first turned our readers on to in the Aug. '09 issue's "Hot Off The Press" column. Hopefully we can provide future updates as the project progresses.