Brake Line Question
 

I have a 1970 SWB Stepside with a 1972 front end(disc), a 1972 differential, and power brakes. The main brake lines on the truck are the original 1970 manual lines. Don't ask me how I got them to work...i don't remember. When trying to purchase brake lines I notice there are two different sets listed for a 1972 C10 2WD Disc Front with power. What would be the difference? I know some sets go over the frame, and some under the frame up front. Is there anything else?