Depends on where you use it.
For the tranny, you MUST use a GL-4 specification oil because the tranny has yellow metals (brass, etc) in it. GL-5 can ruin it. Most RedLine oils are GL-4, but not all. Mobil 75w-90 synthetic is definitely GL-5.
I used Mobil 1 75w-90 in my differential because it has no yellow metals. Just this past weekend, I switched my tranny to a 50/50 mixture of Redline MTL and MT-90. Both of these oils are GL-4 compliant.
Checkout Redlineoil.com for complete information on the specifications and weights.
350Z Track in Daytona Blue (#16,962)
Engine: Crawford plenum, UTEC with tuner wideband and in dash gauge
Transmission: Z1 motorsports flywheel, JWT clutch, B&M Short Shifter version 2
Intake: Injen short ram intake, K&N cone filter
Exhaust: Crawford headers, Kinetix cats, Borla true dual exhaust
Brakes: Track model Brembos, Stoptech two-piece rotors front and rear, Pads: Hawk HP+ track, Hawk HPS street, Ate blue racing fluid, Goodridge stainless braided lines
Wheels/Suspension: BBS RSR 18", Kuhmo Ecsta MX tires, Cusco A-arms, Stillen rear toe arms, RSR Ti2000 springs, Hotchkis sways
Interior: Complete stereo swap, iPod stereo integration, and dynamat