Are the factory tanks galvanized inside and out ? If they are then I don't think you can weld on them, correct ?

So then, to add a sump, or attach anything to the tank, is brazing your only option ?

I have installed sumps on new galvenized tanks by welding them after grinding/sanding the coating off. It works fine for me for over 15 yrs of service….street and track. I just clean the i side of tank out very thoroughly.

Exterior and interior view

I did the same thing, but tig brazes with silicon bronze instead of welding.

For what its worth,there are more ways to get uninterrupted fuel flow from a stock tank without welding on a sump. I used an in-tank pump that feeds a remote mounted surge tank to feed my EFI'd motor. Simple plumbing including adding an upsized return line provides me with airless continuous fuel flow even when the tank is down to the last gallon or two.

Modified a factor style fuel sending unit, added a narrow piece of Holley Hydromat to it (not pictured) and bolted in a surge tank. Easy and much more effective than using just a sumped tank.

Hmm. JBC, that is very interesting !

I also have an external sump setup for the EFI system I am putting on the flathead six in my 51.

It is essentially a remote oil filter setup using a spin on fuel filter as the sump. Stock mechanical pump feeds the setup, external high pressure pump draws from the filtered side of the setup, return from the fuel rail feeds back into the setup and a return line fromt he sump goes back to the tank.

Sniper, i would like to see a picture of that if you have one.

No pics, but here is a link to the guy I got the idea from

http://madscientistmatt.blogspot.com/2005_12_01_archive.html

I thought so too when I saw it. The pump in the fuel tank circulates fuel from the tank to the surge tank and back at high volume at nearly 0 psi. The in-tank pump free flows the fuel from tank to surge tank in a continuous loop, which keeps the surge tank full even when the fuel tank level is very low.

The surge tank pump circulates the high pressure fuel through the fuel rails, to the injectors, then to the pressure regulator and back into the surge tank.

These two circuits keep the high pressure surge tank full, while purging any air induced into the surge tank by the low pressure side when the fuel level is very low.

When you add the Holley Hyromat to the main tank, induced air is virtually eliminated at the source.

I'm about to double the horsepower and consequently the required fuel flow the system can provide. All I need to do to increase the fuel flow is to upsize the fuel pumps in both tanks.

Here is another idea. Fuel surge and pump tank.

Yes, I liked the video. While he retained the stock fuel system to show the ease, simplicity and quickness of installing his upgraded components, I opted to upsize my feed and return lines to allow for higher flow rates to the surge tank I installed. Another reason was that I am running a 5.9 Magnum based motor with no stock fuel pump on the motor.

I used a Radium Engineering surge tank, which was available several years before McRob put his set-up out. He makes nice stuff.

Look into Holly hydra mat. I can run 2-3 gallons in a stock tank and not have supply issues.