jmoore - If you could post pictures of your current setup, it would help identify if it's stock or something else. I have a 1955 GMC Model 100-500 Shop Manual, but it doesn't provide a diagram of the lines. The only hard copy GMC Master Parts Book I have for 1957 is a 1955-57 Chevrolet/GMC of Canada Book given to me a by a generous fellow Bolter. It does have a drawing, but it's lacking in clear details, just a general this line goes here/there/etc. I think it's actually the same drawing as in the US 1957 Chevy Master Parts Book. Gotta go look at that one.
