So after some trial and error replacing intake manifold gaskets, I learned the hard way a certain year model vehicle does not always have that same year model parts. My 2000 F150 4.6L has a '99 engine. At very least the upper intake manifold and cylinder heads are different between those years.

Is it safe to say the entire engine and all its internals are '99? Does anyone know if anything else changed between '99 and '00, like A/C, radiator, etc?

 

The intake manifold may be different but not the cylinder block!

 

My mistake, ment head. Edited post.