If you are using the front engine mounts and a rear crossmember only, that is a long stretch. Causes the engine/trans to flex too much.
Is this rebar supporting anything?
My opinion....I think that you should be looking into side mounts for the engine, and a new crossmember for the tranny. Sounds like someone has butched this pretty well.
Either that or find some proper mounts for the bell housing.
Any pictures of this "mess"?