The V6 camery box isn't out of an SV21, the S at the start indicates the it had an S series engine in the car. But i've been told the V6 camery box is a good box to use, the SV21 box can also be used but it isn't that strong and will probally break with in the first few thrashings.
I'm using the MR2 turbo box with an LSD. I can't say this enough, that if u r going for the FWD 3SGTE conversion u need an LSD. I have had a couple of ppl say that they just can't get the traction down, and they get fed up with the new performance/handling. I'm willing to give out information on the conversion but if u r not going to put an LSD in to it don't waist my time.