Difference between oil pans

Is there a difference between a 65 and 66 273 oil pan? I am mocking up my 66 empty 273/235 to my early A K frame as I need to fabricate the transmission crossmember for the 42RH. the front of the oil pan is sitting on the K even with the transmission tail-shaft lowered a bit. I’m using the brick insulators if that makes a difference. Thanks for any insight or suggestions to solve this issue