I'd be tempted to try it as-is and see how it works before buying new pods and injectors. If you go down just a couple of psi on the fuel pressure, you can still get a good spray pattern. I've seen TBI systems running as low as 9psi with a bad pump or regulator and the injectors still spraying well. It's not hard to make the factory regulators adjustable, they've just brazed over the adjustment screw. If you can't get the fuel flow low enough after that, then I'd look at injectors/pods. I'm no expert on flatheads, but I would think they'd need a little more fuel than a modern head design for the same amount of power anyway. I think I might try putting TBI on the Continental flathead 6 in my Clark Planeloader soon. How far away are you from firing it up?