I have seen that the 12-1.5 mm lug nuts were used on trucks built prior to 11/29/1999 and that 14-1.5 mm lug nuts were used after that.
I think I saw some 14-1.5 mm locking lug nuts in an Autozone yesterday in Easton, PA. However they had tapered seats. Don't remember the brand since I think the "L" wheels have a flat seat & I wasn't buying.
It is just a matter of time before they are readily available, especially if all F-150's and Expeditions are using the 14-1.5 mm lug nuts from 2000 on out.

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2000 Lightning Red
2" lowered rear
LeBra slim line soft tonneau
Ford Front cover
Super white headlights
Superchip

 

12mm or 14mm?

Chrome or black?

(so many questions, so little time)

 

From the comments I've seen I'm now wondering if they are shipping me the correct parts. As soon as I get the parts I will post here to let everyone know if they work out.

 

Just an update on the locking lug nuts.-- Just received the set of 20 and they are chrome and they do fit!! The locking nuts are ~1/4 inch longer than stock but they look fine. The nuts have tapered ends and come with washers made for the nuts. Please see above with order and contact info.