Center Cap Help

[shell]

My boyfriend has a 1999 Chevy Silverado and recently got new tires and rims. They are missing the center caps and I want to get him some. My question is how do I find the right ones? They have 6 lug nuts that are threaded. I know they are GM, and I bought some caps off the same truck but the lugs on the caps were too short. Is there an easy way to determine which ones I need? Trying to be a good girlfriend and surprise him but not knowing about trucks I am just clueless. Any help would be appreciated! Oh the tires are 16's if that makes a difference.

[Chris]

Post a pic of the wheels and we can steer you in the right direction

 

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