I currently have the old Borg Warner 7.75" 9 bolt in my IROC with the crappy 2.77s. With the new cam I am installing, I will want deeper gears ASAP and ACAP (as cheap as possible). I don't need anything radical like 4.10s or anything. I'd be happy with 3.2Xs, 3.4Xs or even 3.7Xs. I don't care, 9 bolt or 10 bolt, discs or drums. But I will have to have a speed shop swap rears or gears, so thats gonna cost some $$. I just need to find the cheapest way to do this, all suggestions are welcome!

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission with 2.77:1 Rear End

Current Mods: LT4 Hot Cam, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Gutted Catalytic Converter, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, Fully Ported TPI Plenum and Base, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

 

swap a new rear in from the bone yard!
Thats cheap!!
Nitro Don

 

Ditto....I found a wrecked 90 IROC, and swapped the rear to my 82 firebird, and then into my current IROC. POSI... 3.23 and the nice aluminum calipers...and it bolted right in with no mods. Those of you swapping from drum to disc rears may have to fab an adapter for the brake lines (my 82 had large tube drum lines, and the disc rear had small tube)....



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Mike Metzler (Desert86Roc)
Mike@SpeedworldMotorplex.com
[*] Webmaster: SpeedWorldMotorplex.com[*] Click Here For My Racing Page[*]86 IROC 305 TPI (406 build in progress)
ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.365 @ 86.785 mph (uncorrected, Headers, no NOS)

 

look in 1985-90 camaros with 6 cylinders,most of them came with 3.42s.i got one out of an 88.firebirds may be the same

 

Thanks guys, anyone know of any salvage yards in northern colorado? Also, what will a complete rear end cost me?

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission with 2.77:1 Rear End

Current Mods: LT4 Hot Cam, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Gutted Catalytic Converter, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, Fully Ported TPI Plenum and Base, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

 

I was looking for a complete rear myself. I found that a one legger will go for $150-200 and the posi axles will go for $300-450!!

I found a 3:73 rear and am putting the SLP take-off posi unit in it. If you go my route, make sure that it has 28 splines!

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• 89 Formula 305 WS6
  SFC's,
  LCA's,
  Air foil
  Flowmaster cat back
  Tranny Cooler
• 90 Eagle Talon 2.0
  (winter beater)

 

Yup, V6 Firebirds from those years (altho I thought it was from 85-88) also have 3.42/open/drum axles.

I scored a 3.73/posi/disc axle from an '84 Trans Am for $150. That's a rare axle, offered between '83 and '85. If you find an '84 t/a in a junkyard with engine code "G", and a manual transmission, then chances are you've found my axle!

Of course, in the junkyard, pull the cover & check all the ring/pinion teeth out before you buy. It's also a great time to double-check the ratio.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

I've got a 9 bolt posi from my '87 IROC with 3.27s in it. I'd sell it for $250 but shipping will kill ya. It would have to go truck freight. It's got discs on it also.

 

Anyone else have any ideas or anything to say?

------------------
1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission with 2.77:1 Rear End

Current Mods: LT4 Hot Cam, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Gutted Catalytic Converter, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, Fully Ported TPI Plenum and Base, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)