Spec for Dist. bolt

[achoeypatkul@hqfaus01.unicef.org (Amnat Choeypatkul)]

     Hi Q-Listers (& Bill Brace),
     
     My '89-90 (non-q, auto) has been making tapping noise (someone said its 
     sound likes a turkey) under the hood--from the distributor area.  I'm 
     thinking about taking the distributor out & clean it up--by fishing out 
     the "mushroom" bolt which holding the distributor to the block.
     
     Could anyone of us--who'd BTDT, pls give me some hints on the spec & 
     size of this bolt.  (Bill, do you still remember the spec/size of this 
     bolt?  I'd like to get the bolt before I start fishing it out--because 
     I have no second car nor bicycle, and the nearest "Pep Boys" is about 2 
     miles.)
     
     TIA,
     Nat
     '89-90 non-q (70+K miles w/ a turkey under the hood)
     
     Internet: achoeypatkul@unicef.org