1997 Chevy Blazer blown engine

Check to see if it turns over, listen for knocks and or clunks. Under 1 spark plug at a time, checking cylinder pressure per spark plug hole, if the pressure isnt way different than specs, it's blown. But it may just be the intake gasket, thats VERY common in the 6 cylinder vortex. So if you check those and the pressure seems lower than spec., you may want to start tearing the intake off, you should see gasket failure, if not, keep going the head gaskets may have blown. Change them all when putting it all back together. Buying a manuel will help if you dont have one already. Or get a very good machanic, make sure the "machanic" himself has the good rep. There are a lot of them giving the rest a bad name.