I am making a fuel return block and my current return barb fitting has a 3/16" ID. I am assuming that this is too large and I am planning on adding a fitting to the inside and just drilling the required hole size.
My old filter with a return line has a 1/16" hole for the vapor return and the psi held steady at 6psi at idle. Should I drill it at 1/16" or just let the return line have the 3/16" ID to keep the fuel moving?

Note: This is for an electric fuel pump.

Thanks