346 @ 18psi on a 63mm is really sad, especially for a stand alone. There are a handful of 1JZ's with SAFC2, 550s, and GT35R's (61mm) doing over 500whp on 18. One of those being about 30mins down the road from my house. In fact, he did around 530whp on the dyno on pump(SC, 1jz, GT35R, MKIV...