The 56A is not really happy with the extra torque of the A15. The 60A's last a little longer. . .

I run an L series pressure plate which I believe could be a part of the problem. I found that the stock clutches don't handle a lot of power, slip under load when new.

Of course a lot of this can be attributed to your driving style.

Keep an eye out for a 63a or celica conversion. Or drive it like grandma.

Once you get bearing noises, it is a good time to swap 'boxes. Throw a set of bearings in the noisy one and it is ready to go in again. Leave it in too long, and . . .