Bed rail size

[JAFO]

A co-worker informed me today that a local discount store has vinyl tonneau covers that fit the pre 99 trucks on clearence...  I realize that the trucks were redesigned but would the frame of the cover be a different size?  Can't eye ball a difference but figure they must have pulled in the rear of the box for more "aerodynamics".

 

Of course the 99+ covers are still going for $120 but the pre 99 ones are on clearance for $40.  You can see why I'm interested.  

 

For those interested and in the upstate part of SC these are in the K-Mart in Greenville.

 

Thanks in advance for any and all help.