c.rogan,
That is the Drain/Cleanout plug and its on the same end of the tank as the pick up tube.
its possible that the PO took out the plug and put the pick up line in the drain hole to alleviate a weak fuel pump or worse,a Rotted thru pick up line.
John,
You are correct.
My 51 Subn tank is still not reinstalled yet and I just went out to measure it.
The fuel line connection is about 5 3/8" up from the bottom and on the same end as the filler pipeand drain plug.
It is "sweat",or soldered if you would,into the side of the tank.
I had mine boiled out at a friends radiator shop.
Kenny also made mention of the side pick up and He Unsweat and took it out,to make sure the Inner Pick up tube was TOTALLY sound,no rust and intact.
He then Resoldered the fitting/pickup tube back in before Seal coating the inside of the tank.
I dont know what the stuff is but was told its impervious to all the ethanols and additives and such so i,m not worried.
Well worth the C Note to have piece of mind.
Regards Steve Sr.
