Ford
You can’t throw a stone these days without hitting an aftermarket aluminum cylinder head. They perform as good or better than anything the factories put out, and then some. They are much lighter than iron heads, and they’re now extremely affordable. Thanks to competition in the aftermarket, it could easily be said that for the performance and price benefits of a new set of aluminum heads, why would anyone bother refurbishing a set of iron castings?
The jump in boost pressure upped the power output from 559 hp to a whopping 613 hp. The peak torque was up as well, from 513 lb-ft to 545 lb-ft.
