I heard a lot of things about installing navigator 4 valve heads on 5.4 engines ?
Is it possible to convert a 5.4 3valve engine in a 5.4 4valve ? If so, what would be the advantages and how much would cost, parts + labor.

Thanks.

 

It probably can be done, but the payoff likely wouldn't be worth it. Look at the new Mustang 4.6 3V engine. They are thowing down just as much power as the older Cobra DOHC engines. At best you are looking at a few more peak horsepower/torque and a higher powerband. You could probably get into a complete supercharger setup for what the conversion would cost you.

 

I was wondering how much this kind of job would cost.