ToxicWS6

right now my cars been turboed for about 2 years or so, turbo seals are starting to go and im looking at getting a new turbo, current turbo wasnt specced out at all when i bought it, did little to no research and i just kinda went with it when i got it. its a masterpowers t76 q trim (ill post specs below) for the longest time ive been thinkin it was on the large side and i could drop down to ether a smaller 76mm or a large 70mm to get spool time up as this is a roadcourse/time attack car, well lookin up more specs and what this turbo was designed for its lookin more like the exhaust side is to small for my car even being the the larger of the 2 76 MP sells, read some where and if i could find the site sellin/recommanding it, it says it was made around the 3.0L engines, which is obviously a lot smaller then a 6.0, that being said, for engine specs and this turbo, how well is it sized, too small, too big, about normal for engine size?

engine is lq4 bored .020, turbo cam and 317 heads running 14psi, around 600-700rwhp

turbo specs as found are this

Compressor
A\R .72
A\R inlet 101.7
A\R Outlet 66.0
IND Wheel 76.5
EXD Wheel 103.5
Trim 55
BL 6
Turbine
A\R 1.00
inlet T4
V-BAND
DIVIDED
EXD wheel 67.0
Ind Wheel 74.0
trim 82
BL 10