The fuel line from the tank through to the mechanical pump is S/S braided line as fitted by Kirkham. The line from the mechanical pump to the carb is a hard line of 3/8" O.D., which is the correct size for the Holley fuel manifold.
The carb is a Holley 750 DP.
I did check beforehand on the forum and many people seemed to be running electric and mechanical pumps in tendem.
Here is a picture of the filter, fitted immediately before the Holley pump.
Thank you.
Paul