Fuel system

[Saltshaker]

Building a new Cobra that uses a gas tank from a early Comaro/Firebird. Is there any advantage to drill and weld a pickup from the bottom of the tank? I could use the original pickup as a trturn line.
Motor is a 428 with a Carter Mech Pump. In my other Cobra I need a electric pump so it would pull in 3rd & 4th on the track.
Job

[Falcon67]

I did that in an tank for the Falcon before I updated it to using a 15 gallon fuel cell.  Pickup on the bottom of the sump using a cut down bulkhead fitting, and a return line through a similar fitting on top of the tank.  The original pickup line was plugged.  I can't comment on the mechanical pump because I haven't used one in 30 years.  Electrics are all I run.  I like them much better than any mechanical pump.