Found some EFI-related stuff for El Caminos if anyone ever wants to go that route. I may be well behind the curve on El Camino-specific stuff, but this was in case anyone wasn't sure and wanted to go with a stock EFI tank/sender. It should take you right to '85 4.3 TBI El Camino, & you just search from there.
http://www.rockauto.com/catalog/raframecatalog.php?carcode=1042715
http://www.rockauto.com/catalog/raframecatalog.php?carcode=1042715