1980 Camaro Differential Related Issue

Grumpy

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
I have a 1980 Camaro that I modified for Bracket Racing in 1990. I removed the 305 V8, T250 Tranny, and 2.56 rear gear. I added a 406 V8, reworked 993 heads (bigger valves and porting), roller hydraulic cam, headers, T400 (no trans brake), posi track 8.5 in rear end with 3.73 gears. Drove to-from track, bolted on 9 in slicks, best time was 12.37 at 108 mph. Parked it in 1998 (my big mistake, did nothing to store it), now my son has convinced me to get it running. That’s my background, this is my question. The brake system is extremely rusted. I need to replace the master cylinder and all brake lines. I plan on converting to rear disk brakes instead of the reworking the old drum brakes. I have to remove the axles to do the conversion. Should I replace the rear axles? They are stock and I believe they are my weak link and hate to break one at the track. I estimate about 400-450 HP to move my 3840 lb car down the track in 12.37 sec. How much HP and torque can stock axles handle and suggested aftermarket axles that I could replace them with?

Thanks for your suggestions and I have a feeling I will need more advice as I try to get this car back on the road and to the track, hopefully sometimes next summer?
Click to expand...

to my way of thinking this is almost a TOTAL NO BRAINER, :rolleyes:
ID swap to a FORD 9# differential, with disc brakes in a serious race application.
ESPECIALLY in this particular application with a fragile 10 bolt differential, rather than what you're currently using without a second thought
imagine what happens if you snap an axle at high speed ,
with the 10 bolt and the rear axle leaves the car at speed,


http://garage.grumpysperformance.co...ill-that-10-bolt-rear-hold-up.273/#post-68923

http://garage.grumpysperformance.co...ve-shreaded-your-10-bolt-rear.237/#post-43106

http://garage.grumpysperformance.com/index.php?threads/big-block-vs-10-bolt.4525/#post-54170

http://garage.grumpysperformance.co...a-camaro-or-firebird-to-bite.4067/#post-10821

https://m.roadkillcustoms.com/rear-end-widths-classic-american-cars/


Chevy / Chevrolet
Outside Width Year Model
57.75 1962-1964 Chevy II/Nova
57.75 1965-1967 Chevy II/Nova
58.00 1978-1988 Chevy Malibu, Monte Carlo
59.50 1968-1982 Corvette
60.00 1955-1964 Chevy Car
60.00 1967-1969 Camaro
60.25 1968-1979 Chevy II/Nova
60.50 1984-1995 Corvette
60.50 1964-1967 Chevelle
62.00 1955-1959 Chevy Pickup
62.50 1968-1972 Chevelle
62.50 1970-1981 Camaro/Firebird
Ford
Outside Width Year Model
56.50 1969-1977 Maverick 8″
57.00 1974-1978 Mustang II 8″
57.25 1957-1959 Ford, Ranchero, Station Wagon
57.25 1965-1966 Mustang
58.00 1966-1977 Bronco
58.00 1964-1965 Falcon
58.00 1977-1981 Granada/Versailles
58.50 1977-1981 Versailles
59.25 1967-1970 Mustang, Fairlane, Comet, Cougar
60.00 1967 Cougar
60.00 1958-1960 Edsel
61.00 1964-1971 Ford Full Size
61.00 1949-1951 Mercury
61.25 1957-1972 Ford F-100 Pickup
61.25 1960-1964 Ford Full Size
61.25 1971-1973 Mustang
61.25 1967-1973 Torino, Ranchero, Fairlane
63.00 1970-1979 Ranchero & Torino
63.00 1972-1979 Ford Full Size & Intermediate
63.50 1967 Fairlane (Coil Springs)
65.25 1973-1986 Ford F-150 Pickup
65.25 1978-1986 Bronco
65.25 1973-1986 Ford Van 3/4 Ton
68.00 1972 Ford Van 3/4 Ton
69.25 1977-1986 Ford E-150 Van
Mopar
Outside Width Year Model
55.60 1960-1976 7 1/4 A-body
55.60 1973-1976 8 1/4 A-body
55.60 1966-1972 8 3/4 A-body
55.60 All 8 3/4 A-body
56.00 1932-1934 All Mopars
57.40 1963-1972 7 1/4 A-body
58.54 All 8 1/4 F-body
58.54 All 8 1/4 M-body
58.54 All 8 1/4 J-body
59.00 1935-1936 All Mopars
59.14 1966-1970 9 3/4 B-body
59.20 1962-1970 8 3/4 B-body
60.00 1937-1948 All Mopars
60.70 All 8 3/4 E-body
60.70 All 9 3/4 E-body
62.00 All 8 1/4 B-body
62.00 1971-1974 8 3/4 B-body
62.00 All 9 1/4 B-body
63.40 All 8 1/4 C-body
63.40 1971-1974 8 3/4 B-body S.W.
63.40 All 9 1/4 C-body

read linked info
https://www.jegs.com/tech-articles/9-inch-ford-rear-axles.html

https://speedmaster79.com/newsroom/9-inch-ford-rear-axle-information

Ford
Outside
Width Year Model
56.50 1969-1977 Maverick 8"
56.50 1990-1992 Ford Ranger 8.8"
56.75 1995-2003 Ford Explorer 8.8" Narrowed w/2 short side axles
57.00 1974-1978 Mustang II 8"
57.25 1957-1959 Ford, Ranchero, Station Wagon
57.25 1965-1966 Mustang
58.00 1966-1977 Bronco
58.00 1964-1965 Falcon
58.00 1977-1981 Granada/Versailles
58.50 1977-1981 Versailles
58.50 1993-2009 Ford Ranger 8.8"
59.25 1967-1970 Mustang, Fairlane, Comet, Cougar
59.81 1995-2003 Ford Explorer 8.8" 31 Spline Disc Brake
60.00 1967 Cougar
60.00 1958-1960 Edsel
61.00 1964-1971 Ford Full Size
61.00 1949-1951 Mercury
61.25 1957-1972 Ford F-100 Pickup
61.25 1960-1964 Ford Full Size
61.25 1971-1973 Mustang
61.25 1967-1973 Torino, Ranchero, Fairlane
63.00 1970-1979 Ranchero & Torino
63.00 1972-1979 Ford Full Size & Intermediate
63.50 1967 Fairlane (Coil Springs)
65.25 1973-1986 Ford F-150 Pickup
65.25 1978-1986 Bronco
65.25 1973-1986 Ford Van 3/4 Ton
68.00 1972 Ford Van 3/4 Ton
69.25 1977-1986 Ford E-150 Van

Chevy

Outside
Width Year Model
54.25 1983-2004 Chevy S10 2WD, GMC S15 2WD
57.75 1962-1964 Chevy II/Nova
57.75 1965-1967 Chevy II/Nova
58.00 1978-1988 Chevy Malibu, Monte Carlo
59.50 1968-1982 Corvette
60.00 1955-1964 Chevy Car
60.00 1967-1969 Camaro
60.25 1968-1979 Chevy II/Nova
60.50 1984-1995 Corvette
60.50 1964-1967 Chevelle
62.00 1955-1959 Chevy Pickup
62.50 1968-1972 Chevelle
62.50 1970-1981 Camaro/Firebird
Mopar

Outside
Width Year Model
55.60 1960-1976 7 1/4 A-body
55.60 1973-1976 8 1/4 A-body
55.60 1966-1972 8 3/4 A-body
55.60 All 8 3/4 A-body
56.00 1932-1934 All Mopars
57.40 1963-1972 7 1/4 A-body
58.54 All 8 1/4 F-body
58.54 All 8 1/4 M-body
58.54 All 8 1/4 J-body
59.00 1935-1936 All Mopars
59.14 1966-1970 9 3/4 B-body
59.20 1962-1970 8 3/4 B-body
60.00 1937-1948 All Mopars
60.70 All 8 3/4 E-body
60.70 All 9 3/4 E-body
62.00 All 8 1/4 B-body
62.00 1971-1974 8 3/4 B-body
62.00 All 9 1/4 B-body
63.40 All 8 1/4 C-body
63.40 1971-1974 8 3/4 B-body S.W.
63.40 All 9 1/4 C-body
GM & Mopar Body Style Codes
Last Update: 07/04/17

https://www.fordmuscle.com/archives/2002/02/nineinch/http://carnut.com/iown/40ford.html

http://www.mustangsandmore.com/ubb/FordRearDimensions.html

1965-1966 Mustang 57.25 inches
1967-1970 Mustang 59.25 inches
1971-1973 Mustang 61.25 inches
1977-1981 Versailles 58.50 inches
1967-1973 Mustang, Torino, Ranchero, Fairlane 59.25 inches to
61.25 inches
1957-1959 Ranchero and station wagon 57.25 inches
1966-1977 Bronco 58 inches
1977-1981 Granada/Versailles 58 inches
1967-1971 Comet, Cougar, Mustang, Fairlane 59.25 inches
1971-1973 Mustang 61.25 inches
1964 Falcon 58 inches
1967 Cougar 60 inches
1967 Fairlane 63.50 inches coil springs
1972 Ford Van 3/4 ton 68 inches
1973-1986 Ford Van 3/4 ton 65.25 inches
1957-1959 Ranchero and station wagon
57.25 inches
narrowest 9" housing
1966-1977 Bronco 58 inches 5-on-5 1/2 inch diameter bolt circle
1967-1973 Torinos, Rancheros, Fairlanes 59.25 inches or
61.25 inches
1967-1971 Comets, Cougars, Fairlanes 59.25 inches

https://www.therangerstation.com/tech_library/9InchAxles.shtml#:~:text=1971-1973 Mustang 61.25 inches,station wagon rears, 57.25 inches



Axle Widths:

  • 1965-1966 Mustang 57.25 inches

  • 1967-1970 Mustang 59.25 inches

  • 1971-1973 Mustang 61.25 inches

  • 1977-1981 Versailles 58.50 inches

  • 1967-1973 Mustang, Torino, Ranchero, Fairlane 9-inch 59.25 inches to 61.25 inches

  • 1957-1959 Ranchero and station wagon rears, 57.25 inches

  • 1966-1977 Bronco 9-inch, 58 inches

  • 1977-1981 Granada/Versailles, 58 inches

  • 1967-1971 Comet, Cougar, Mustang, Fairlane, 59.25 inches

  • 1971-1973 Mustang, 61.25 inches

  • 1964 Falcon 58 inches

  • 1967 Cougar 60 inches

  • 1967 Fairlane 63.50 inches (coil springs)

  • 1972 Ford Van 3/4 ton 68 inches

  • 1973-1986 65.25 inches

  • 1957-1959 Ranchero and station wagon 57.25 inches (narrowest 9-inch housing)

  • 1966-1977 Bronco 58 inches but has 5-on-5 1/2 inch diameter bolt circle

  • 1967-1973 Torinos, Rancheros, Fairlanes 59.25 inches or 61.25 inches

  • 1967-1971 Comets, Cougars, Fairlanes 59.25 inches

  • 1974-1986 F-150 65 inches

  • 1978-1986 Ford Bronco 65 inches
Where To Find:

  • 1967-1973 medium and big block Mustangs and Cougars

  • 1966-1971 Fairlanes, Torinos, Montegos, Comets, and other Ford intermediates with big blocks

  • 1957-1959 V8 Fords and Mercurys

  • 1977-1981 Lincoln Versailles & Trucks
Ford F-150 9-Inch Axles:

The Ford 9-inch can be found under 1974-1986 F-150s and 1978-1986 Broncos. It features the legendary Ford 9-inch ring and pinion strength, 5-on-5.5 lug pattern (same as older Jeep), a 65-inch width at the wheel mounting surfaces, large-bearing semi-floating axles, and many can be found with hefty 31-spline axleshafts. Another bonus is that the axleshafts are of equal length, so you’ll only need to carry one spare should you choose to.



Type Of 9-Inch Housings:

  • 1967-1973 Mustang/Cougar - light duty, thinnest housing material, small axle bearings, 28 and 31 splines

  • 57-68 passenger car and 1/2 ton truck - medium duty, stronger than Mustang type, 28 and 31 splines

  • Ranchero/Torino - heavy duty thick wall housing, 3.25 inch diameter axle tubes with flat tops

  • 1969-1977 Galaxies (coils), Lincolns (coils), and late pickups (leaf)- 3.25 inch diameter all the way to the backing plate, coil housings have upper control arm mount
How To Recognize 9-Inch Housing Centers:

  • 1957 - no dimples, flat center band up the center of the rear cover, bottom drain plug

  • 1958-1959 - two dimples on back of housing, flat center band, some had drain holes

  • 1960-1967 - two dimples, flat center band, oil level hole in back cover

  • 1963-1977 Lincoln, LTD, Thunderbirds had 9.375 inch centers, housings were cut away at the gasket surface for ring gear clearance, one curved rib at the front top portion of differential, strong but no gears
Types of 9" Axles:

  • 28-spline axles cannot be shortened and resplined (they're tapered)

  • 1972 and earlier 31-spline axles have the ability to be shortened

  • 1973 and later 9-inch (cars) have a 5-on-5 bolt circle and the axles cannot be shortened

  • 1967-1973 Mustang axles identified by wheel flange:
    • oval hole - 28-splines

    • two large holes and counter sunk center - 31 splines
 
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