Some guys were talking about this the other day on this board. The solder the sump after its welded on to make sure it doesn't leak.

Look into running a surge tank too. They are amazing, especially the ones from Radium Engineering.

I have a stock tank with no baffles and can get down to a couple of gallons in the tank on a road course like Willow Springs and never have any problems with air getting into my high pressure side.

I run a simple external pusher pump in the back of the car(it's a bit noisy still), but it just flows fuel to the front mounted surge tank at near zero psi until it is full and then it flow right back out to the main fuel tank again. Any air bubbles float to the top of the surge tank and are sent back to the main tank immediately. A high pressure pump at the bottom of the surge tank full-bypass flows through my fuel rails with air free fuel and dumps back into the surge tank too.

I'm doing some other work on the car right now but before it goes back on the road, I'm going to switch over to an in tank pump with four of those Walboro screen pick-ups in each corner of the tank.

No baffles, no sumps just a solid stream of un-aerated fuel to the injectors or carbs until the tank is almost empty.