I did a search on "6R80" but didn't see an answer on the variation (if any) of the 6R80 transmssion that is currently being dropped behind the different F-150 engines.

I have heard that with the 3.7L engines, a "smaller" 6R80 (with fewer plates in the clutch stacks) is used, but is the same-sized 6R80 tranny otherwise used in the EB, 5.0, and 6.2 powertrains that have higher torque numbers?

 

read link>>> http://www.fordf150.net/2011/2011-fo...ansmission.php

it confirms your suspicions on fewer clutch plate when its bolted behind a 3.7.....however the 6r80 is still the same size...

 

Thanks 88!
I am intrigued by this statement from that posting, "In every case the transmission has been optimized to each new engine..."
That indicates to me that the 6R80 is somehow made different for each of the three larger (more HP / torque) engines as well.

 

Maybe there is different spacing on gears on each engine?