I've also got this turbo in the .64ar version it spools real quick full boost (20si)by 4k rpm and holds boost all the way to the redline, its not quite a direct fit though needing a modified oil return if you bought it from atp turbo insted of Allen you would also need to setup the turbo housings and make up a new actuator bracket and probably get a smaller actuator aswell which could be ackward to do
all this comes already done if you bought it off allen (apart from the oil return)
If you were to buy this turbo you'd be best off going for the larger 0.84ar(or is it 0.86) one as the 0.64 one suffers from compressor surge quite badly when on part throttle which is really annoying to say the least
the larger version is supposed to not have this problem due to better balanced housings.