[A Snake]

I played with Jags for years with nary a problem. Simple fact is Jags don't make enough hp to break parts.

When I got my Contemporary, I got it with the watts linkage kit. My S/O made similar hp numbers to what you describe. I drove the car hard on and off the track and my only problem was the piddly little allen bolts used to secure the center pivot for the watts linkage. I'm not sure of the correct name for them, but they had a 1/2" shank which shouldered and became 3/8" thread. If the linkage wasn't adjusted to pivot freely throughout it's entire range, those lovely little bolts would shear off. Finally got it set right and the bolts quit shearing. Later I learned that some folks were drilling out the hub carrier to 1/2" thread and getting on very nicely with no more broken parts.

I did a lot of things that should or could have broken rear suspension, but I never had a failure like yours.

What I haven't seen mentioned is the amount of "fresh" metal showing in the break. To me, it does look more like fatigue, than the torn look one would get from a weld letting go.

Just a few thoughts.

Al