im gonna get a b16 or b18c5 tranny for my gsr. witch one would be best for the track? and does it matter if its a usdm or jdm tranny? and what is the diff between the 2

GSR tranny is the way to go.. It got better gear ratio... and if on the highway.. GSR tranny will tear b16 ass up..

Out of all the motor swaps that we have done i have found out that you should go with the tranny that fits the motor. The b16 you will find that the tranny is geard alot diff because it is not biult to take the gearing ratio for a b16si motor the b18 is geard alot better and shorter gears.

are you talking about the gsr (b18c1) or the itr (b18c5) tranny? the difference between these is that the itr tranny has lsd and a higher gearv ratio. the gsr is still good and really good if you want performance and still want the gas mileage.