OK, first and foremost, Supras do not have struts. Supras have dampers (or call them shocks if you like), not struts. The part is misnamed.
If it fits on a Supra, it is, at best, simply a pillow ball mount. (these aren't see below). On a car with McPherson Struts, the strut connects the hub assembly directly to the chassis of the vehicle. There is no upper control arm - this is what allows the camber and caster angle to be adjusted from the upper strut mounts. On a car with upper and lower control arms like the Supra, no changes at the upper mount can effect the caster and camber of the suspension.
The advantages of pillow ball mounts on a car like the Supra is that they restrict the movement of the top damper shaft and make the movement more linear. This provides better steering feedback, but also can make the ride feel more "harsh" under certain conditions. However if you're not running coilovers, I doubt you'll notice much improvement with pillow balls at all. They may make the ride more noisy however.
But, the most important point here is that the Moog part isn't even a pillowball mount.. Yes, the photo at Summit looks nice, but if you read the fine print it's:
Summit Racing said:
Image is a representation of this part. Actual part may vary.
And in this case that is
very is misleading. The Summit photo looks like a nice ball bearing strut mount. The actual part for the Supra is this one (image taken directly from the Federal-Mogul (Moog) website:
Here's what a real pillow ball mount for a Supra looks like:
