Hi, you can get a .36, .48, .55, .63 exhaust (and prob more) on a t3, and usualy the last three on a t34, and both turbos have various AR compressor sizes too, i am using a t34 .63 ex with .50 inlet on my v6 cosworth. .63 can be used on a 2 litre but is considered a bit big, power would come in at about 4000 rpm, a .48 is more like 3000, but will run out of puff at 6500, wheras the .63 will rev another 1000, hope this helps