I need to replace my 5/16 fuel pick-up with a 3/8. The bends in the new one (junk from Taiwan) were way off, and it would always bottom out in the tank when installing it. I couldn't return it, so I corrected the bends, but the sock on the new one is twice as long so it still bottoms out. Due to the shape of the bottom of the tank, if the sock was the same length as the original 5/16, it would fit fine.
Searching parts catalogs tells me that the same tank was used for big block and small block cars, and 3/8 sending units are supposed to have the long socks. It doesn't seem to add up unless the 3/8 bends are supposed to be different so that the end of the tube is in the same spot as the 5/16 and the range of the float is still correct.

Is this a common problem? Can I just shorten the end of the tube and get a shorter sock? Would a shorter sock support the extra fuel flow? Is it easy to change the sock? Thanks!

If possible, it makes sense to have the filter sock sitting parallel to the tank bottom to expose more of it to fuel during the lowest level. This will allow you to run the tank level down to near dry, and to avoid fuel starvation. I did this by cutting the top off of a rusty Duster fuel tank and test fitting the sender. I would bend the inlet tube, test fit, remove and bend, etc until it looked right. Unfortunatly, the Chow Mein quality gave inaccurate guage readings.