Where to get the correct 360 oil pan.

The pan I bought is a center sump.It is simply to small to go over the rear main.I think they must have packaged it incorrectly,put a 318/340 pan in the box instead of a 360 pan. I still have the pan which came on the engine ,it is rear sump.I have a phone # to call and give them some measurements.I will do that tomorrow.If they fail to correct the problem I will go with one of the kits you guys spoke of .I guess buyer beware. :glasses6: