Only issue I have with the 94-96 Impala 140amp alternators are not being able to use the rear support bracket that bolts the assembly to the manifold stud.
You're OK, As long as you're running HR Parts Poly engine mounts, but if you are still using a ratcheting strap to minimize engine movement then you've got a concern as the extra stress / torque over on the unsupported alternator assembly could lead to an early demise.