Tilton designed their flywheel to accept a pilot bearing. If a pilot bearing was used, you would have to modify the end of the input shaft to locate in the pilot bearing. Also, the noise you are hearing is most likely from the tranmission. The EVO tranmission (maybe due to its "play") seems to be sensitive to the harmonics/vibrations coming from the engine. Since the Tilton use solid hubs, there is not sprung hub to absorb the harmonics/vibrations cause by the engine firing.

 

With all the speculation, I thought I might clear up a few things. Tilton makes a great clutch, especially their carbon/carbon. As with any part, you have to understand the benefits and tradeoffs. You have to remember that the Tilton is more of a race clutch and the noise is considered normal and in racing noise is not usually a big concern. For some, the noise is going to be considered objectionable, and to others the noise is going to be considered an acceptable tradeoff. There are three different types of noises people normally refer to. Here is a brief explanation of each:

The squawking sound upon engagement from their cerametallic is from the interaction of the friction material, not the transmission, pilot bearing or the lack of springs in the disc. Maybe a pilot bearing, different trans or springs will change the noise (doubtful) but the untimate cause is the friction material.

The gear rattle or decel noise is normal for a disc that has no springs or inadequate dampening in the disc center section. That is the downside along with rapid spline wear. The benefit is that the disc(s) are lighter and easier on syncros. The engine's torsional vibration is the source of the rattle and is usually dampened out by the heavy weight of the flywheel and dampening in the disc center.

The floater rattle noise only occurs when the clutch is disengaged because the parts will hammer on the posts that are used on most multiplate clutches. This also is from torsional vibrations. No harm occurs, but it is annoying to some.