The pan in this picture hold 6 quarts if memory serves, and it sits even with the bottom of the K-member. I did have to cut out a small V-shaped notch on the seam of the K-member to clear it.
Do you have any pics of it installed in your car, showing how low it hangs in the car compared to the K member? I have a 68 Barracuda that I am putting a 360 Magnum in and looking at this pan.