Are center caps different in size?

[jstang209]

i have a set of wheels on my 79 but the center caps are missing, I think these are the stock rims, but im not for sure. The rims are 16 inches and the center cap is approx 6 inches. So if i got some center caps from some ponies or 10 holes will they probably fit these rims?

 

[wythors]

79's didn't have 16" rims. Post a pic and somebody can help identify them.