So another thing I noticed was my lower intake didn't seem to fit correctly to the 97-98 intake manifold. Am I also going to be in the market for a 99 lower intake manifold? Is there any difference between them?

Bluegrass, what do you think?

 

I have not followed all the replies but there is a difference between NPI and PI heads.
The intakes are different for port matching.
Since your not sure what you bought you will have to follow through with identifying what you have and need.


Sorry I can't be of more specific help.
Good luck.

 

Actually I think I somewhat figured it out. I apparently have a 99 5.4L NPI head and intake. I have teardrop shaped intake holes on both the manifold and block. I bought a 98 intake gasket set, and it matched perfectly, however, the nipples did not line up whatsoever on the gasket so I cut them off.

The truck runs a million times better. But I'd really like to know what damn motor I have in there. Doesn't make any sense.

The 99 Intake manifold gaskets align with the nipples, but it's got round tear drop shaped holes. So confused here. Can't be a 97-99 Cause then the gasket would have fit. Can't be a 99+ cause then it would be PI.

The whole issue turned out to be the fact that every piece of information out there points to PI intake gaskets, and they flat out don't fit. They were on the truck when I bought it.

 

Is there such a thing as a 99 5.4 non pi?

 

The PI heads are marked "PI" on the part # stamp on the heads.
Non power improved heads (NPI) have been retroactively designated that but are not marked as such so they will not have "PI" in the part # on the head.