think all the other expenses you have going to that size turbo. Ideally in order to fully extract its potential you need 740 cc inj and a built motor. The GT28r is about a $100 less + you can get by on a stock internalled motor at full boost.
Ohh btw Z1 675r is NOT 2530 its slightly different and its more like 650 not 675 :)
Harry
Formerly yellowzxtt
" If it doesn't make it faster, i don't care " Please visit www.ztuner.com to GO FASTER