And an update....
Pulled the stock mount out in the dark this evening, ripped on both sides of the L-bracket. Managed to singe my arm on the top of the valve cover working on it while it was too hot, but thats my fault.
Turns out I couldnt get my jack underneath the engine, so I just lowered it off the existing mount a few turns at a time, and then undid the mount from the frame of the car.
I put the new mount on, tightened it down to the frame good and tight, tightened the through bolt until the poly just started to pucker, and then I tightened the bolts up on the engine a few turns at a time until all was snug.
Waiting until tomorrow to test drive, but does anyone see anything that might be bad about installing in that sequence?