The torque arm in the M9 is going to make a little noise when you go over bumps, but it isn't bad. The M9 torque arm assembly was designed to clear the tunnel in our cars, and even lowered cars won't have a problem with it. The M9 is also the same weight as the 10 bolt, so you wouldn't be adding any weight to the car.
The Moser Extreme Axles which are gun drilled and star flanged, are not recommended for street use as they can't handle side loads as well as the standard axles. Bob

 

Are you sure there isn't enough clearance for the M9 with the Watt's link? I'm not that familiar with the Watt's link, but from the pictures below it looks like it should fit to me. Bob



The watts link frame mounts in existing holes and factory bolts from the panhard bar.




Close up view of the passenger side shows the watts link installed in the factory panhard bar and panhard bar brace location.



Watts link mounted in drivers side factory holes with factory bolts.



Close up view of the drivers side shows the watts link installed in the factory panhard bar and panhard bar brace location.

 

This is what Sam Strano had to say about the Watts Link not fitting the Fab 9 rears...
https://ls1tech.com/forums/10665147-post22.html

I guess the axle tubes are just too big for the clamp assemblies that the rod links connect to.

 

The axle tubes are three inch, same as the standard Moser 9 inch. The only thing I can think of is possibly the fabricated center section protudes back to make contact with the Watts Link. Bob

 

First time I have seen a Watts link. What is the benefit of all that other than keeping the rearend cetered up when being compressed?

 

Keeps the contact patch of the rear tires firmly planted while cornering. No one has spoken ill of it yet in any way, only good things have been said, even for a drag car.

 

12 bolt spool. Its nice to see pat g's old TA in new hands. 600rwhp on the spray, nice!

 

Is a spool better or worse in the corners than the locker?

 

A spool locks together both axles for good, so when in corners the inside tire won't be able to turn fewer rotations than the outside tire. This causes the tires to scrub quite a bit. In reality the only time I've noticed it is when making a turn in an intersection, or trying to make a u turn or when trying to parallel park.
A locker is going to release the inner axle in a turn to allow it to tun fewer revolutions. Bob

 

well, i guess somebody made the watts link works with a fabricated housing

http://www.totalcontrolproducts.com/rpss_fd.html

 

I have seen this many times on late model Mustangs and this setup is in fact for a Mustang. With extensive fabrication, anything is possible but it just won't work on the Fays2 f-body bolt-in Watts Link system...yet.