Will it fit

[Westcraft]

Would an Optiplex 790 MT motherboard fit in a 390 MT case

 

[Pentium4User]

Would an Optiplex 790 MT motherboard fit in a 390 MT case

It should since they are both atx and don't have built in io shield, BUT I noticed one thing, the front panel connectors on the motherboards looks different, Unless you want to rewire it then it should work.