Thanks for the YT advice Franco Cozzo.
Just comparing the GM plan with what Ford is doing:
GM has reworked its old iron block vortec line to make the new 6.6, basically has the
same 4.06" bore as the 6.2 but a longer 3.85" stroke along with Gen V DI and VCT....
Funny part is that GM is sticking with the 6L90 and not upgrading to a HD 10-speed auto.
That would be equivalent to Ford just increasing the bore and stroke on the 6.2 Boss
and calling it job done with the 6R140 6-speed auto - Ford would get panned for that
but GM gets a pass because well, it the GM small block underdog taking in big bad Ford.
Thank goodness Ford went with a two engne strategy, the 6.2 continues in F250 with a
base 6-speed auto and optional 10-speed auto while the 7.3 V8 is available across the
whole F series range.
The new GM 6.6 V8 is rated at 401 HP @5200 and 464 lb ft @4,000 - HD truck power ratings
are de-rated roughly 30 HP and 30 lb ft less than light duty F150 /Silvy 1500 power specs.