What I found strange about routing this line under the upper control arm, is that with a real good bump, it looked like the control arm might make contact with the line; possibly kinking or even severing it. When I got everything done, I put the car on the ground and bounced the right front as best I could. I tried to simulate a real bad bump. I didn't hear or feel anything. Put the car back up and checked the line as best possible. Didn't see any signs of contact, Carmine.
If you are worried about clearance just jack up front center of frame and this let's the upper a arm come down to hit the rubber bump stop and check the clearance .If you mounted line as factory locating clip's location you should not have any issue's. As far as getting in the fuel line under arm just place jack nest to wheel and separate upper ball joint and swing arm up to gain access to line clip's . Don't need to tie jack down. I don't remember any problem's getting the line's in as I think I put it in as I had frame out and assembled line then,but I don't see a big problem getting the line in since it has a rubber section close to front body mount right front and you can install that section by it self. Don,,,,, I think you worry to much. If you are not racing hard core you can put in factory location. I mounted mine factory though tunnel. I can see if you race like Ray to route different,but then you have heat factor to make sure that is not a issue either. I would think that if this was dangerous Gm would have recalled these car's year's ago on a street driven car's.I have never heard these car's catching fire's for that problem. I have seen carrier bearing 's get loose on rubber mount and drive shaft jump ,but the metal loop keep's it confined,and warn you if that happen's. I once lost a rear u joint in my then new 64 409 ,but it did not do any damage to line as was further ahead of joint, of course I was racing hard when I lost the rear joint. Every body has their own opinion's on this ,your car ,,,,,do as you want!!!