Turbo is a 3.54 rear.
http://www.geocities.com/MotorCity/Garage/6212/diffswap/diffswap.htm
280ZX
79 MT 4 Spd, (3.364) (R180)
79 MT 5 Spd, (3.364) (R180)
79 AT (3.545) (R180)
80 MT (3.545) (R180)
80 AT (3.545) (R180)
81-83 w/o Turbo,MT (3.9) (R200)
81-83 w/o Turbo,AT (3.545) (R180)
81-83 w/Turbo (3.545) (R200)
ZX 2+2
79 MT 4 Spd, (3.364) (R200)
79 MT 5 Spd, (3.7) (R200)
80 MT (3.9) (R200)