OK, thanks guys. I modified the sending unit for 38 gallon tank with 5/8 pickup and -6 return. This was a couple years ago for a project that has been sitting. Anyways, back on the project and the sending unit won't work.
Decided to go with a beans sump and asked about the filler neck return. I am now looking for a replacement sending unit to use the 3/8 supply as the return. If I can't find one, I may be back to the filler neck.
Thanks again.