Deep sump oil pan

Rather than cut and add a piece between the two, make a square cornered sump and weld to the pan. You'll be suprised how much more volume there will be with square corners than rounded.

If your real handy cut of the flange around the K frame and weld then form a sump close to the that shape with a square cornered bottom bumped out a little on the one side. This will give loads of volume in that limited space. Did this on my sons Demon.