Factroy GM TBI needs ~11 PSI uninterrupted fuel pressure. Finding a suitable inline pump may be difficult. Although I've never searched for a standalone inline substitute, neither have I discovered one inadvertently. Too little pressure will cause significant drivability symptoms. Too much pressure will heat the fuel unnecessarily. In addition, electric pumps function better as pushers, so drawing fuel from the tanks through a selector valve may prove troublesome on a pressure-sensitive TBI system.