No way in hell would I ever do that. 58 psi is a decent amount of pressure to be trusting to a simple hose clamp, which is all the Spectre pieces are. Plus, the hard points are not beaded connections, so the hose would have nothing more than the clamp to hold it in place. The hard lines are designed for SAE J2044 connections, and those are what should be used IMO. I understand that doing it right isn't cheap, but starting an engine fire because you wanted to pinch pennies isn't sound logic...
Aeromotive 15118 - 3/8" hard line to -8AN line (the feed and fuel rails are 3/8")
Aeromotive 15117 - 5/16" hard line to -6AN line (the evap line is 5/16", which some people use as a return line to the tank)
Russell 640850 - 3/8" hard line to -6AN line (blue)
Russell 640853 - 3/8" hard line to -6AN line (black)
Russell 640860 - 5/16" hard line to -6AN line (blue)
Russell 640863 - 5/16" hard line to -6AN line (black)
The fittings on the top of the tank are the same way, with two 3/8" hard points for feed and return, 5/16" for the evap system in the middle, and the fuel filter is also a 3/8" SAE J2044 type of fitting.
Personally, I don't like the Russell fittings. They work, but the Aeromotive pieces work better IMO (and unfortunately have the price tag to show for it).