Since everyone is helping out with the recessitation techniques, I'll tackle the transmission part of your question. I thought a T10 was a 4 speed but I could be wrong, I do know that the T5 in my Z works great. With a world class T5 and 350 hp you should be fine, if you want to beef it up a bit the counter gear stabilizer from gear zone is a good upgrade. As long as you can refrain from dumping the clutch and speed shifting this transmission will do okay. Get a T10 if you want to abuse it, or a T56 if you want to be abusive in more gears
Heavy Z