904 leak...dipstick???

Just trying to eliminate all the obvious...I have a '73 Dart Swinger 318 2bbl with an A904 automatic trans. I get a leak when I park it, not alot, but over time it adds up. Checked the pan and everything is good. I have a dry rotted trans mount and am going to replace it as soon as the weather gets warmer. I guess what I'm wondering is would an old dry rotted tranny mount cause the tranny to vibrate or sink lower and wiggle the dipstick loose?? Any help would be greatly appreciated, Thanks!