Just passing along some information. I have been plagued with what I thought was clutch &/or throw out bearing chatter for some time. I have even pulled the motor/trans a total of 4 times to try to solve this problem with no success. The other day I sent Joe Lucia an e-mail and ask him for an openion. He suggested I replace my flywheel cover with an improved GM# 354497 cover. I did and the chatter went away. It appears the original was rubbing on the crank and vibrating. The improved version clips to the oil pan instead of sliding up between the bell housing and the block.
Thanks Joe
Thanks Joe