I am new at this diesel thing and just purchased a used 2003 that was orginally purchased in Oaklahoma and made in mexico.
How can I tell if I have a SO OR HO?

 

Being that its a 6 speed you have the H.O. But there are a few other ways to tell. Look on the right side of your engine, there is a engine data tag . you cant miss it. You can tell buy the h.p. rating. Or look at the V.I.N # if the 8th digit is a C it is a H.O. , if its a 6 is an S.O. Hope this helps

 

Thanks and I do have a "C".
my wife says I am tooo old to learn anything new!!! haha