[Supras] Help! New vibration MKIII Supra Turbo - at 72mph+postmechanical work

[Koll]

Noticed something else in your original post.  New Goodyears...

One of the cheapest and best bangs for the buck at this point would be to 
have those sucker balanced.  Sure, Pep Boys and every other monkey in the 
business has a "computer balancer".  Whatever.  Find out where guys with 
Ferraris, etc. go to have their tires balanced "on the car" and make an 
appointment.

You might just find some of that 20% go away.

After all, it is a variable you changed from your original (non-vibrating) 
setup.  Always check the stuff you messed with - no matter how "good-to-go", 
"no-brainer", etc. the fix/upgrade/while-you're-in-there modification was 
done.

At the very least, do a tire rotation (assuming you have uni's - 
front-to-back) and see if the behavior is exactly the same.  If it isn't - 
you have a balance issue that's contributing to the chain of failure.