Since the Garmin GPSMAP 8012 & GPSMAP 8212 have same spec’s more or less as the GPSMAP 8008/8208 – (Which you can find here) I will not dive into specs here.
I will just give you a comparison on sizes on the Garmin 12″ displays and a little extra info.
As you can see – it is more or less a direct swap for the GPSMAP 5212 and GPSMAP 7212. If tolerances are tight I think you can swap over directly. But remember – they do not come cheap the new 8000 series. Almost $5000 for the 12″ 8212 pack with external GPS19x bundle.
And I will say – it is hard to tell the difference in size from the pictures Garmin has provided. But here are a couple:
And for those who want’s more – here is the link to the spec’s on Garmins own website: https://buy.garmin.com/shop/shop.do?pID=110004