return should be as big or bigger than feed line .
1/2" to reg , 1/2"return .
In saying that I used 3/8"return , into tank sender , for years . But when I finally went to 1/2"return I had to readjust fuel pressure a little higher . That tells me the 3/8 was a restriction .

Tex

New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm
Power by Tex's Automotive