JBL Synthesis ~ any year 05+ head unit work in an 04?

[AZ~4runner]

Does anyone know if will any year 05+ head unit work in an 04?
I have steering wheel controls, 8" sub & Synthesis system with an OEM head unit and cassette player attached.

I want to know if I can swap out the head unit for a new JBL head unit with a six-disc head unit in it.

Can this be done? Will everything work correctly? Thanks!