I have an 89 IROC-Z 350. After punching in my RPO codes I find that I have a 2.77 rear ratio. I look at the tech data, and I see that there were two different 350 IROCs the 2.77 and the 3.27 rear. Why were there two different rears available? Isn't 2.77 a little too small? What are the pros and cons of the 2.77 and the 3.27?

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6 months and counting... the search for a Camaro goes on...
... and now finally I got one, hell yeah!!!

Would you like it if the next generation of kids, start sayin daddy, daddy buy me a fast and powerful car, like a Honda Insight?! NO!
Muscle is muscle, stop this fighting between american cars, we must join and defeat the world!

1989 IROC-Z Camaro
5.7 Ltr
Ram Air
Cat-back Flowmasters
K&N Filters
-my first car, my dream now reality

 

They usually offer a few different options for rear end gears in all models.

2.77 is good for highway cruising.

3.27 is better for performance.

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

 

Right, but define "performance". My 277s let me cruise down the road at 145 without breaking into the 4500 RPM range. That's pretty good performance for a little engine. Of course, it sucks at the line...

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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader

 

Yeah, but if you have 700r4 in front of it, those 2.77s will be like 3.27s on any other car

 

Yeah I can back that up with my 2.77's and 700r4 its like having 3.73's on the highway with those things my car is at 120 its about to enter the 4000 rpm range


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1988 Camaro Iroc-z
305 ci Tuned Port 700R4
3" Exhaust/Flowmaster 80 series muffler/Dynomax high flo cat
hypertech chip/k&n filters
Cut out MAF screens
TPIS Airfoil
"Camaros RULE!!"
"Theres no replacement for displacement"
SAVE THE F-BODY!!!!

 

The difference in gears depends on your personal preference. I had 2.73's in my TA and I recently switched to 3.23's with posi-traction. With the 2.73s I had a lower tach but when I put in the 3.23s I could tell a big difference in power. My car tachs higher now, but it's got more power up through the rpms. Personally I like the 3.23s/3.27s but if you like a lower tach then you might prefer the 2.77s. At 120 mph I'm just over the 4000 rpm range. But with the extra power I think it's worth it.

 

Nothing wrong with having 2:77 Gears.

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1987 Black Camaro IROC-Z (original owner) Replaced LB9 @ 86100 miles.
New 350 Crate engine
Balanced & blueprinted
World Prod SR 67cc Heads 9.6:1 C.R.
Cam: 454lift,216dur@50,110ls
TPI Induction(from 305)
22# Fuel Injectors
AFPR & Gauge
SLP Intake runners
Fastchip stage 2 chip
K&N filters & Air Foil
Hothkis STB
SLP 1 3/4 Headers
CATCO 3" Catalytic conv.
SLP 3" Cat Back Exhaust
700R4 Auto
SLP Torque Converter (2400 stall)
1LE Aluminum Dr Shaft
B-W 9 bolt rear 2:77 Possi. Four wheel disc brakes,245/45/ZR-17 Tires
17x8.5 ATI 5 Razze Wheels
Dyno results: 211 RWHP & 282 RWTQ.
271 HP & 362#/ft at flywheel with all Emission controls installed. New Toy!