prevent problems on northstar engine

Answering for completion

While you can switch oil types, it isn't quite a drop-in replacement unless the engine is known to take it well. The Northstar V8 is already infamous for being a particularly needy engine which is plagued by issues like buried water pumps which are multi-hour jobs to access; especially ones under the top head where you not only need the gaskets but also a water pump. Some are prone to blowing the engine young with lower-grade oil as they age. These are not engines you do a half-assed swap on unless you want to invite potential problems :-(. These are already semi-infamous for blowing up as it is.

The right way to do it on an engine established on traditional oil is you need a product like an Amsoil engine flush kit which has it's own oil. Once you do that and get the Amsoil stuff out of the engine, then you switch it over to quality full synthetic like Mobil1 (Yes, the full synthetic SuperTech oil is probably similar enough but the Northstar V8 is mildly infamous as you pointed out) and stick to that to avoid issues in the future. Oil changes will not be cheap once you switch it over but on an engine that is higher maintenance like these Northstars, the extra $5/bottle outweighs the cost of replacing a blown Northstar with a rebuilt one and paying for it anyway to avoid new issues on your rebuilt engine. Pay the extra now and save what you have.

While synthetic blends are a thing and can sometimes negate the need to flush these "notorious" engines, I don't think they're a good idea when you're trying to avoid problems on fickle engines. If you have a rock-solid engine that's older and want the benefits of synthetic for less they make sense.