I bought and used a stock Mopar 6 quart oil pan for 1970/71 B and E body Hemi and 440 six pack motors with the stock 3/8 440 six pack oil pick up in my 1971 Duster pump gas low deck 512 C.I. stroker motor, I did move the motor back one inch for weight distribution and I ended up notching the K member a tiny bit to clear the right front corner of that pan
That oil pan is not real deep, the sump is long and does not hang down below the stock A body K members
All the after market 7 quart oil pans I've seen and used do hang down below the K members enough to scrape in parking lots