The G33m02 is a depopulated [cheaper] version of the motherboard that has only has 6 voltage regulator IC's, as opposed to the 11 voltage regulators on the G33m03 motherboard, that supports both Core 2 Duo and Quad Core processors.
The G33m02 motherboard can be replaced by the G33m03 motherboard, but, the power supply also needs to replaced by a 350w+ unit, instead of the default 300w unit installed with the G33m02 MoBo.
The Inspiron motherboards are built by Foxconn to Dell's proprietary specifications.
Regards to installing a non-Dell motherboard, probably best to use a Dell specification motherboard, as the BIOS will accept Dell OEM software, eg operating systems, plus it will match the Dell chassis front panel wiring connectors.
Ps, I still have a 9 year old Inspiron 530 MT, with a G33m02 motherboard that's been upgraded with hybrid hard drives, Windows 10 and a LGA 775 e8600 processor