ROAD RUNNER FUEL PICK UP TUBE???

I HAVE A CUSTOMER IN NEED OF A FUEL TANK SENDING UNIT/PICKUP TUBE FOR HIS 69 ROADRUNNER 383 FOUR SPEED CAR. i CHECKED ONLINE AND SPECTRA HAS THREE DIFFERENT PIECES LISTED. DIFFERENT LINE SIZES AND AN EXTRA HARD LINE COMING OUT ON SOME SAYS FUEL RETURN. DOES ANYONE KNOW WHICH ONE OF THESE I WOULD NEED FOR THE REPAIR? ANY INFORMATION WOULD BE GREATLY APPRECIATED. THANKS IN ADVANCE.

I'm thinking (1) 5/16 (2) 3/8 & (3) the special one with an extra nipple for a fuel return (which can be capped if not useing a return). senders are the worst of the worst for improper readings sent up to the dash gas gauge so definitely do your homework on this one. there have been several good threads on this in the last several weeks, see if you can retrieve em or someone my post a good company to do business with. Have your customer slip a 5/16 and a 3/8 open end wrench on the short metal nipple on his sender to see what he has now. OE would not have the return nipple so that elims that one of the three. But the problem is getting one that electrically reads right.

The return line was only used with 440 and hemi engines - not 383.