808:
""just searched on NAPA's site, found a #3041 which has 3/8" nipples""
Good note, I didn't know they had one with 3/8 nipples!!
I would guess that the vapor will rise to the top and the filter would have to stand vertical with the 1/4" return to the top.

TB3:
Yep, my $65 YO unit is in my attic now. I was told by another member that they are making one of the holes in the piece too large allowing the fuel to run back thru to the tank. Too bad because they "look" like nice pieces. I bought mine two years prior to actually installing it so I couldn't send it back.