Completely possible! I just did this exact thing on my truck. I used stock, 1978 non-baffled tanks, 2x Holley fuel pump modules, and a Harnessworx LS harness with a new Pollak valve that can handle EFI pressures. You can check out my install here:
http://67-72chevytrucks.com/vboard/s...d.php?t=806842