3-valve swapped into Chris Payne’s Fox notch.

There are quite a few options out there in regards to mod motor engine swaps, and there are many reasons to look into throwing one into that old Mustang. Maybe that Fox-body has racked up thousands of miles, or maybe the motor has already gone kaput and is spending its days doubling as a fancy lawn ornament. Maybe it’s just time for a little bit more power paired with increased reliability. These days there are kits or control packs with everything you need to perform your modern swap of choice without too much hassle.

While researching engine swaps, there are two modern swaps that seem to be the norm when browsing car shows, forums, social media, etc. Those two swaps come in the form of the almighty Coyote 5.0L from 2011+ Mustang GTs and the 4.6-liter four-valve Terminator swap from those 2003-2004 SVT Cobras and Mach 1 cars. Every so often we stumble across that towering Lightning swap or the impressive 5.4-liter Shelby GT500 mill transplanted into an older Mustang, but those can certainly hurt the piggy bank making them a bit more unusual.

2003-2004 Cobra “Terminator” swapped into a Fox-body.

Every once in awhile you’ll stumble across a three-valve swap from the 2005-2009 GT cars, and if looking on a forum or social media, they seem to be most unappreciated. So, what’s wrong with the three-valve? The engine seems to be dependable and reliable, and it is surely more affordable than most. If found in a salvage yard or out of a wrecked Mustang, you can find one for dirt cheap. Sure, those new 5.0 engines make a bit more power out of the gate. They are certainly very aesthetically pleasing under the hood however, the price for a new stock 5.0 or Aluminator crate engine can put out a good sized dent in that bank account. Even a wrecked Mustang GT 5.0-liter engine demands a premium from the salvage yard.

In regards to power, a stock three-valve engine has over 300 horsepower. Of course, the newer Coyote 5.0 is good for over 400 horsepower without additional modifications, and the Terminator four-valve cars produce 390 horsepower out of a supercharged 4.6-liter engine. However, if going with a naturally aspirated four-valve engine, the horsepower from the factory was rated at 305-320 horses. That means that the three-valve and four-valve engines put out the same amount of power.

Coyote crate engine swapped into a 2008, a car that normally houses a three-valve engine.

As mentioned earlier, Ford Racing offers a Control Pack that is supposed to take the nightmare out of the three-valve swap wiring nightmare, that obstacle of wiring has deterred many from performing the swap. This Control Pack has all of the Ford Racing parts needed to get the 4.6-liter three-valve installed, such as PCM with Ford Racing calibration, electronic throttle control acceleration pedal, Power distribution module, air box with inlet tube and filter, MAF sensor with bolts, EGO sensors and wiring harness. The kit includes everything necessary to make the swap as hassle free as possible and only costs about $1,300.

While browsing forums and asking friends why they think that the three-valve doesn’t seem to be as popular as other mod motor swaps, we found that besides the wiring headache, that the engine just isn’t as cosmetically appealing as the other available mod motor options. We think it looks rockin’ in Chris Payne’s Fox-body notch that we covered last month.

Sure, the two or four valve 4.6-liter is a cheaper option than some, but is it worth the hassle? Why is the four-valve chosen as a swap more than the three-valve considering that both naturally aspirated engines are putting out very similar numbers? Is it really the three-valve engine really that ugly under the hood or is there something more to it?