[joelN20]

At the auto part store they say they have two different size rotors how do I know which ones to buy?

 

[alexcor]

it should be one size for the 4cyl. and one for 8cyl.
the 5.0s i think are 11"

 

[EagleAutosports]

Should be a 10.75 inch, or the 278mm, depending on what store you're going to.

 

[joelN20]

thanks for the help I thought that maybe one was for the 4cyl and the other for the 8 but better safe than sorry