FWIW...I don't think I've ever mounted one that was below the fuel level on my own cars. I always use the inner rear frame rail on the passenger's side. Never had a problem yet.
Holley blue, Aeromotive street rod pump, and my current Aeromotive A1000.

CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax