So after some reading, Eaton says the Gen V results in a 9% increase in horsepower. Based off of the 240HP the L67 produces, that is 21.6HP. The general consensus that I've seen is that a 3.5 pulley will net ~20 HP. A 3.6 (or a swap to a Gen V) would be around 12-17HP increase, giving a 5-7% increase. Is it really that hard to believe? I don't think so. Eaton probably took credit for all the other improvements GM did, the larger throttle body, the better tuning, etc to get to their "9%" increase.
