Harmonic balance removal
 

Hi-- I have a 2002 duramax diesel,4x4, with a leaking water pump. I have tore it down to the bolt that attaches the harmonic balancer. Can anyone tell me what size the bolt head is?
I have been told you will need a 6 or 7 foot "cheater" bar to remove this bolt. Is this true?
Thank you in advance for all your help.

Slopoke:s: