I have a T5 tranny, and was using a 3.90 with it. With the T5 first gear, I HAD to short shift it, which was doubly hard - no boost, and hit the rev limit if I wasn't careful. I did this over and over at the strip -- pi$$ed me off. I finally went back to the 3.54, and found a useful 1st gear again. Still not full boost in first, but some, maybe 5 psi. Second gear was real nice though, the look on the WS6 driver's face when I pulled him from a stoplight was PRICELESS!