[Night Enforcer]

Sounds like you are on the right track in checking every thing out. KEEP THE RETURN FUEL LINE! Depennding on the fuel you are using (oxygentaed etc) it will save you a lot of headaches with vapor lock. In Arizona vapor lock can be a big issue due to the heat and the fuel mixes. In tests, some of the oxygentaed fuel we get in TUcson and Phoenix begins to "boil" at 160 degrees. I have installed return lines on 6 Cobras including a Kirkham which has two fuel pumps, an electric and a mechanical. Solved the dreaded vapor lock.