the z31 t3's on KA motors put down between 200-250whp from what i've seen so far, nice upgrade for cheap on a KA with a jgs log, great for a budget setup. for an SR id pick the gt28/s15, they are in better condition, that price on cheapturbo.com for almost $800 is pretty decent, most s15 ones i used to see were around 850, and ballbearing will put the s15 > z31 in terms of spoolup time. the KA owners ive talked to who have it are hitting full boost in the late 3k's, 3800-4100, take charles' setup for example of s15 on sr and hes full at 3400 or so.

even with a z31 and rebuild like slash and scott say, there is the manifold/fluid lines/o2 turndown to rework