I have an 07 Classic with the LBZ. I could swear this transmission shifts six times from zero to 55 mph. The engine likes to live at 1500 RPM. Each upshift results in a 4-500 rpm difference shifting at approximately 2000 rpm and back to 1500. This is on a very easy 'egg shell under the pedal' start. If I push the gas a little bit, like on a quick start to get on the highway with traffic from a dead stop, the shift occurs at about 2200 rpm. The last shift occurs at 55 mph and always takes me to 1500 rpm..

Six shifts = seven speeds. Is one considered a granny low or an overdrive? Am I just hearing things?

no its a six speed. You may be feeling the torque converter locking up... I feel it when getting on the freeway on the 4-5 shift. It kinda 'lugs' into 5th unless i'm hard in the peddle.

X2 on what Jason said. The "shift" you feel at 45 is the torque convertor locking.

Yeah, it is just the torque converter. Some slippage is required for smoother shifting. Then it locks in for less power loss in the drive train after a shift has completed. I believe it is only in the overdrive gears (5th and 6th) unless tow/haul is on (somebody correct me if I am wrong).

BTW, overdrive simply means any gear that is less than 1:1 (which is 4th gear in your truck). 5th and 6th are both overdrive gears.

Jerry

nope ,its only got a 6spd, the 5spd's used to feel like a 6th gear , but its just the converter locking up