Try removing the starter and looking through that hole, or sometimes there's an access plate at the top of the bellhousing. The Hydramatic has something like 26 bolts holding the fluid coupling housing to the flywheel, and the Allison might have somethiong similar. I've got a GMC 401 in my fire truck, but it's got a 5-speed manual trans.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!