67cuda 360 oil pan issues

we are putting a 360 from a 1978 dodge van into my 67 barracuda conv. We removed the pan from the 360 and installed the pan from the 1972 318 that was in the car only to discover that the rear pan sealing area is larger on the 318 pan leaving a gap to large to seal up can any one offer a solution to this problem? Thank you. Pat.