Thank you for the write-up. I'll probably do the transmission mount as it looks easy and it's what bothers me the most. As for the engine mounts... that looks like a PITA. If I do headers then, I'll do the engine mounts at the same time.

Did you notice much increase in harshness or vibration?

No increase in NVH.

OK, so I bite the bullet and installed the mounts this weekend. My observations from the installation.

1. Remove as many of the heat shields that you can to gain access.
2. Passenger side was able to get a wrench on. Leverage was obtained with a strong bar against the frame. I doubt they are put on at 38 ft/lbs. When it gave way it made a loud popping sound.
3. Drivers side is a little bit more difficult, but not much if you raise the engine. The attack angle is from the front. We got a socket under the rear heat shield but was a pain to get out. Just remember to remove the bottom nuts before jacking the engine.
4. Removing the actual mounts was easy, passenger to the rear and driver to the front.

Summary: The transmission was absolutely worth the upgrade. The Z seems to have a lot of drivetrain slop. The engine mounts tightened things up more which is more fun to shift, but also increases the harshness a little. Some may think it's an aggressive growl, while others will think the engine is running rough. Just hope it isn't triggering the knock sensor. I'll drive for a few weeks before coming to a conclusion on the engine mounts.

Mine went into a high idle which triggered a CEL. This was probably due to cleaning the MAF and disconnecting the battery. ECU eventually figured out where idle is and I cleared the code. So no harm, no foul.

UPDATE: After driving it for a few days. I do like the change. NVH is up a little but not to bad considering it's a sports car and not a touring car. Seems like all the upgrades for more power and fun, lead to more noise. At a certain point it crosses into being obnoxious as a daily driver. That point will vary depending upon the person. Idle at the moment is 74db which I think is very good. Cruising around town is 91 db. Measurements from the drivers seat.

Any negative impact on changing only the Transmission mount and not engine mounts at same time?

I bought the Torque Solution Trans. mount. They don't make eng. mounts.

Is Z1 the only viable option for engine mounts?

I have read and seen Drop Engineering, which is a better match for the TS Tranny mount as they are both 75A hardness. (vs Z1 which is 70A...am I splitting hairs :icon14:)

I read an early thread about their demise on a SC 370z.

Theres also BDE:

https://www.bde-performance.com/mounts2.htm

but they are 88A hardness and probably overkill. Nice looking though, and they have factory tabs for easier install.

TIA

zz