The 03'ish year came with forged internals on a 4.6 block. They were able to put in some cheapish internals due to how thick the cylinder walls of the 4.6 are. My friend has one of these with stock internals and has custom Whipple charger on it. Makes 650 to the wheel with new tranny, charger, bolt ons, etc. The stock internals can't go above 19ish pounds boost which is what he is pushing. The only thing that throws me for a spin is the fact that the most they can get out of a v8 with 19lbs boost is 650...guess we can chalk that one up to Ford's primitave tiny v8...[not a ford guy either just like to know about my competition]
