To expand a little, if you have a flex plate, it means you have an automatic transmission.
The following is based off the knowledge i have gleaned from my older vehicles (specifically my 74 Nova), but I'm sure our new trucks are similar enough.
The Flexplate connects directly to the crankshaft with several bolts (5 bolts in my case), which then connects to the torque converter. The TC's job is to provide the fluidic coupling between the engine and the transmission (its what lets your transmission slip compared to the engine speed, and when you rev it up, it keeps the engine in its power band).
Maybe the trucks are different, but why would you need to drop the tranny to count the bolts? Just turn the engine at the flexplate and count them as the go by. Unless you cannot even access the flexplate/TC w/o dropping the tranny which would seem very odd.