[hatzie]

I own a Tech2 and a few older Snap On scan tools that support pre-1996 GM, Ford, Chrysler, Aisan, and Euro vehicles to one degree or another.

Set your expectations.
The pre-1996 Domestic Ford and GM ECMs' don't have much in the way of bi-directional controls but they do have a bunch of useful live data available for troubleshooting above and beyond the "codes" that might or might not trigger the money light.

The Vetronix Tech2 and Chinese clones can talk to most GM vehicles from 1991-2013.

The Snap On MT2500 "red brick" are fairly decent tools for diagnostics on 1980-1994 GM vehicles.

The Solus EESC310, Solus Pro EESC316, and MODIS EEMS300 cover 1980-94 & 1996 up to the limit of the installed software bundle and the unlocked coverage packages. Bundle 10.x covers up to 2010 Bundle 16.2 covers up to 2016 etc.

These tools are no longer supported by Snap On so the software bundle and coverages loaded on the tool or cartridges are all you get and repairs are your responsibility.
The unlocked manufacturer coverage packages are a similar situation.
If you have US Domestic, Asian, and Heavy Truck coverage unlocked, European coverage locked, and the tool is running bundle 12.4 like my MODIS EEMS300 and Solus EESC310, that's what you have til it fails past your ability to revive it.