1972 fuel line differences?

[Mike_The_Grad]

I am kinda stuck on something and hopefully someone can assist me.
I am replacing the fuel lines on my stock 1972 C/10 LWB with SBC350/TH350 and the tank in the cab. I just purchased a 2 piece set of replacement 3/8" main fuel lines for 1971-1972 Chevy C10/GMC C1500 8 Cyl. 2WD. And a 2 piece replacement set of 1/4" return lines because I have a 3-port mechanical fuel pump.
The 1/4' return lines fit perfectly. The 3/8" line from the tank to beneath the cab fits perfectly. The 3/8" line that runs along the frame rail is nowhere close to the 3/8" line I pulled out of my truck. See pix. What am I missing? I'm assuming that there are different fuel lines for the different C10 models for the 1972 production year.
I understand that there are different sizes/lengths/routing for the different chassis (K-series,P-series,10,20,30 series) And different engine sizes (i6,Small Block, Big Block)
I'm only referring to 1972 C10 with Small Block V8.