NA6 Gas Tank Replacement - While I'm In There
 

Fuel tank on my 1990 is leaking at the front seam.

Looks like I need to drop the subframe/diff to get at the tank.
What else should I be changing while I have it all apart?

Also, is there an aftermarket diff bushing solution that has the same NVH as the stock rubber?

Cheers!

I dropped the subframe and tank in the last year or so. It's really not all that difficult, though my car is reasonably rust-free and the nuts holding the subframe on came off fairly easily (your location says Great White North, so I assume salt is an issue).

I used it as an opportunity to remove mouse nest remnants, acorn husks, and all the other crap that accumulated in the area while the car was stored outdoors in New England for a while.

There are some fuel lines that are easier to replace with the tank out, but I'd probably wait until you can actually get your hands and eyes on them before ordering replacements or picking up generic hose.

If your parking brake cables/mechanism are rusty, this is probably your best opportunity to replace them, but even that can be done with the tank in place.

I cleaned a bunch of grime off the subframe, hit any bare metal with some paint, and made sure to clean the threads on the body studs. There's really not much to be done.

Main issue will be rust unfortunately. Have hit the nuts/bolts with penetrant a few times, but it can only do so much.
I expect snapped hardware and brake hardlines. 320k KM on the chassis so it doesn't owe me anything.

Any suggestions regarding the diff bushings?

Unfortunately no… I don’t care about NVH in my track car and my street car hasn’t earned a bushing replacement yet. I’d probably go with stock rubber at that point, if they’re even available.

If you are worried about NVH, stick with the OEM mounts. I found the polyurethane mounts to be intolerable on long road trips.