Conversions & Hybrids - GSL392 internal check valve?

Does the Walbro pump have an internal check valve? If not and the pump is set higher than the pickup (which is probably the case for many of us) a check valve might be a good idea. Thoughts?

no clue on the walbro, but i used a mallory and i had to get a check valve from aeromotive for mine. other wise your priming the system every time you start it.