Does anyone make a fuel sending unit with a bigger pickup?

Mine's original and it's 5/16.


was your car originally a 6 cylinder? if not then someone has either swapped in a 6 cylinder gas tank or sending unit at one time. as i said, the original v8 units were 3/8". i guess it's possible that someone on the assembly line grabbed an incorrect tank or sending unit and installed it, though. regardless it should have originally been a 3/8 sending unit
 
Bad idea. Your return line should always be the bigger of the two lines. That side isn't under pressure like the supply side and needs the help to evacuate.


huh? i've never seen a return line that was larger than the supply line. maybe the same size but never a larger one. the idea is that fuel will be used at a greater rate than it is sent back to the tank, generally.
 
huh? i've never seen a return line that was larger than the supply line. maybe the same size but never a larger one. the idea is that fuel will be used at a greater rate than it is sent back to the tank, generally.

It needs to be the same size at a minimum. But bigger is OK. Smaller isn't.

If you have a huge fuel pump to support huge horsepower, you need a huge return line. At full throttle, you use most (all?) the fuel. When you idle it has to go somewhere. Putting it into too small a return line is a problem on a street car. A straight line race car probablly doesn't care one way or another. Likewise, if you're using a stock 55 GPH deal it doesn't matter.
 
Car Craft has an article that says the exact opposite of what I wrote.

I still don't think I'm wrong, but I might be talking about EFI high pressure pumps and not low pressure high volume pumps for carburators.

Anyway, I apologize for spreading bad tech. My bad.