with out knowing much about the 2.3t I'd go with the 4G63. but then again my opinion may be a little bias. But seriously, the 4g63 is a very strong motor, when built the 4g is capable of making 900+whp..(Buschers evo) and running 1/4 mile ETs of less then 8 seconds.(sheps 1g awd)..but again i know nothing about the 2.3t. just my .02