What's wrong with a 72/75 for a "street car"?
let me see if i can help with that.the larger turbo needs more rpm, alot more stall,better heads, more compression,the right cam and valvetrain,to operate in the higher or more rpm window of usage.your basically moving the power up and waiting to get to the power which is opposite of a responsive street car that needs to get into boost fast to leave the lights better or drop down hits or dig rolls whatever one likes to do.with a 64 or 67 it will lite up whenever you want and cover the op goal of mid 9s using a 72/75 or bigger for a goal like that is just creating lag and lowering response time of the car.