I need some advice.

I have a 2001 F150 Lightning. I bought a set of 4 wheels and tires. The rims are 16" Ford steel wheels and work great. However, the center section needs filled so I went and bought a center cap that is said the work on this rim per their book at a local rims shop.

I've come to find out via this great forum that the lug nuts are 14mm X 2.0. However, according to the shop that sold me these caps, I need to factory style lug nuts that would go with these steel rims and center caps. Apparently they have a indentation or line near the middle of lug nut that the center cap snaps into when it goes on. According to them, if you just snap them into place onto my Lightning lug nuts and allow friction to keep them on, they will come off in a block or to - they've seen this happen apparently.

Now where can I get the lugs nuts????? They didn't have any now that have come off when someone trades in their stock rims. They said they might in the future. They also said the Ford dealer would probably charge me $8 a lug nut -OUCH!!!!

Any advice where I could get some?