if it's a 30/76 the compressor housing should be a .60 a/r if it's a .50 then you have a 30/71, it's a great 400+ turbo (mine's a precision, i love those guys)
we just tuned a buddy of mine's car tonight. red top s13 sr20, gt28/71r .84 (the mid size) 403rwhp /343rwtq? (i forget the tq) @ 18.5 psi, 810cc injectors, z32 maf, power fc, stock bottom end, hg, studs, 264 cams/springs/retainers. i'll look tomorrow at when he hits full boost if you want. also keep in mind our dyno is a steady state mustang dyno, so he'd have bigger numbers (if #'s matter) on a dynojet.
as far as my 30/76r on my rb25, i would get 22psi on 100octane = 3500rpm 350ft lb tq
93octane (pump gas here in GA) 20psi @ 3700rpm
one of my favorite turbo's.....i may be trying a borg warner s262 on my ka-t 510 tho, supposedly quicker spool than 35r but makes more power. anywho look into the borg warner turbos , and if it's a real 30/76r with a .60 a/r compressor housing ur gonna have a helluva time with a stock or megan style bottom mount. not saying you can't get one custom made, but you also have to think about the downpipe and clearing your steering rack with where it's gonna end up sitting....
just my .02, gl with it man, keep us posted on ur build
Dave @ Lethal Injection Motorsports
www.lethalmotorsports.com