I just purchased an 86 Minnie Winnie, which is built on the g30 chasis of the same year, and I've got it in my head that I want to swap out the dash from a later model. Ideally I'd love to install one from the newest models, but I wanted to see if anyone would tell me whether they think it's even possible or worth my time?

 

I'd say no since the new dash unit are all computer controlled, and your 86 is analog.
I would go with aftermarket gauges like Autometer and there are tons of bolt ons in the JC Whitney catalogue.