Have a Garrett GT4088R .95A/R... Turbo would be great for a 600-650, I'm after 800 RWHP as a daily driver, lil smoke, just clean tune.
Do you have a compressor map for this turbocharger?

A lot can be inferred from compressor maps, including smoke, slow/fast spooling, power range, boost pressure, exhaust backpressure, EGTs and a lot more...