I don't want to use solid mounts on my 440 Dart, but I do want much more stable than rubber. I have poly mounts in my '93 Cummins Dodge and they are great, but I haven't been able to find them for the Dart.
What engine mount brackets are you using? Factory, Schumacher, Trans-Dapt? Spool or biscuit mounts? That'll give us a clue of which direction to steer you.