Return fuel system w/ current parts?

50 gph 1/4 NPT In/Out. That pump is not considered high performance in a diesel application, as it was meant to be a replacement for the weaker stock lift pumps on the older dodge trucks(99-04). I'd have to agree, ditch the mechanical, and get a real electric pump for your setup. Do you really see 20psi out of that pump? Typically its under 15psi.