JKH, I guess you want to do the job perfectly. on older trucks, we routinely run new lines alongside the fuel tanks,slip them thru,and zip tie them off to the old rusted line,few people want to pay the labor to drop the tank and do the job so it looks good. Where we can we remove the old lines,and run new from the proportioning valve and back to a new rubber hose,and new line on the rear axles. Once you get the fuel tank down,you'll likey see the tank lines rotted out too. On GM's i oul lthe bed,its much easier,and the job takes less time than dropping tank,if you are working on the ground.