I've got a 727 and 2.94 gears. The car doesn't pull like a 440 should. I'm planning a gear swap for this year. I was playing with a speed/rpm calculator, and according to calculations my transmission is roughly 80-85 percent efficient right now. At 70 mph (verified with a GPS), im turning 3000 rpm. It's a stock, regular low stall factory converter. I understand that the torque converters can wear out so to speak over time, but this transmission also behaves oddly and runs through the gears way too quickly. (There is no time between 2nd and 3rd at part throttle) The line pressure adjustment is correct and the throttle pressure linkage is adjusted correctly.

My question is, how much slippage should there be with a stock converter? I would think only about 5-10 percent.