Electrical/gauge system change in '84?

[CaliWagon83]

There are a lot of cool gauge clusters out there for G-Bodies and specifically the Regal, but I'm noticing in the fine print that a lot of them are made to work in '84 and newer models. Was there a big electrical system architecture change in '84? I know for the Dakota Digital VHX, it requires an add-on control box to work in older models, as well as some cutting and modification of the dash housing. Is this an issue with other clusters? Any experience or information appreciated. Thanks.

 

[565bbchevy]

I believe the only difference is the dash layout with the later years having an open center on the gauge bezel which makes it easier to make a single gauge cluster for, the older ones had separate squares but can apparently can use a modified later model bezel on the older models.
http://www.dakotadigital.com/pdf/vhx_install_early_regal.pdf