Access was a problem when I had the external pump on the rear frame rail in my 65 Newport (for Holley Pro-jection TBI), plus it made a racket thru the rear seat. No problems since I moved it to the engine bay. I know that Holley, etc say you must mount it near the tank and lower, but I am a mechanical engineer and can think for myself. Test the flow from your supply tube. In my cars, the fuel just pours out, so can't restrict the pump. Plus, a Walbro pump can suck fuel up to 5 ft high, if worried about very steep roads. I currently have the Bosch pump (banjo outlet fitting) on my Newport, Walbro (3/8" barbs) on my 65 Dart, and Ford truck ext pump (5/16" barbs) on my 64 Valiant.
