2001 F150 4.2 V6, build date OCT 2000. Trying to replace throttle body, but body and gasket do
not align with the intake. The 4 mounting bolts do, but not the small oblong port. Model year 2000 calls for the same part number gasket. What is that small port, and what difference is there between a 2000 and a 2001 4.2 intake system?

 

I run in to this problem a lot. My 99, 4.2 was built in Sept. of 98 and my truck has a variety of 98 and 99 parts. I have to find out what part I need before ordering or buying a replacement. Can't say I can help you with your specific problem but rockauto pictures might help. If not go to autozone or similar and look at the parts firsthand.

 

It "looks" to me like an EGR port, but I can't say for certain. Rock Auto has 3 different gaskets listed for the 4.2 with no description as to what each is for. It could be a regional thing like they did with the heated PCV valves....

 

Were they the same part numbers between 2000 and 2001? Knowing this the OP can easily figure out if it's a model year issue or a regional issue. Good call White.

EDIT: From the pictures of the gaskets and the TB it looks like the only gasket that might fit is the Fel Pro 61046 which is a very different style of gasket than the one the OP posted.

 

Rivers.....the one you posted is for the ones with air bypass valve incorporated. I do believe you have the correct part. Without the valve, they use a flat gasket, but with, my book shows an oring seal.

 

AK, cool. Honestly I didn't know one way or the other. JMO but I'm a fan of the 4.2 and this was a first for me. Now I know and it's an air bypass valve. I posted the gasket I did only because visually it's the only gasket that would fit what the OP is showing. lol Once more, you come through again.