How does a car feel like that has a broken transmission mount on a 727. Does it viberate at a certain RPM and does it viberate when you bring it off idol in park. What does it do?

Thanks Moparts

Possible but you should feel it on trans engagement worse in reverse I believe and at shift points. Easy to check, get the car up and place a floor jack on the pan with a piece of 2x12 and put some pressure on the jack, if the mounts bad you'll set it begin to seperate, if it a spool type you'll see the center move way too much, a spool type will also appear to be setting low or against metal when relaxed.

I had one rot away. Felt a scraping under the floor pan when taking off fast on a left hander but no noise when doing right handed turns.
However, when cruising normally I had no vibration issues.

for vibration problems under the floor, look at U JOINTS. its Always there