Where can I find an oil pan for a 96 Chevy Lumina 3.1?

I have searched high and low for an engine oil pan for a 96 Chevy Lumina 3100 V6 Automatic. It has about 140,000 miles on it and the oil pan is cracked at the oil drain plug. All I find in online searches is up through 94 for the 3100 engine. Will an oil pan from that year and engine size fit my 96 Lumina? Or can I use an oil pan from a 3400? I'm becoming terribly frustrated. Please help!!