The best tranny to use is the B-series Type R tranny with the H2B conversion. Its supposed to knock 3/10 of a second off of your 1/4 mile time. I used the regular H22 tranny, and they can take a beating. THey H22 Type S tranny comes with LSD, which i would recomend over the standard one because mine spins a lot, but then again mine is nowhere near stock. Also things to note it dosent really affect handling too much like a couple people stated, and i love the torque in them compared to B-series.