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Joined: Jan 2012
Posts: 2
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Joined: Jan 2012
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Hi, I need help. I have a 67 Bird project 400 4speed with a 10 bolt. I pulled the cover tonight to figure out the gear ratio and found it to be a 4.33/1. The numbers on the ring gear are: 39 9 GM 1 67 JA
The ratio is 39 divide by 9= 4.33. I believe the 1 67 is the date code.
How can I tell if this is original and correct for the car?
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Joined: Sep 2001
Posts: 2,902
Senior Member
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Senior Member
Joined: Sep 2001
Posts: 2,902 |
You need the number experts to answer that question. All I know how to do is figure out what's wrong and how to fix it.
A 4:33 is a major serious loose screw. It should haulass like no tomorrow, but I can only imagine the fuel consumption.
If you are trying to verify the raito, you can roll the wheel one revolution, count the driveshaft roations, and it should be pretty obvious.
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Joined: Jul 2002
Posts: 856
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Joined: Jul 2002
Posts: 856 |
I think 3.99 was the most gear you could get in 67. Dose your case have the big loops on the top.(67 only)
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Joined: Jan 2002
Posts: 7,719
Power Member
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Power Member
Joined: Jan 2002
Posts: 7,719 |
Yes, if that rear is real, it's worth a fortune. The "experts" say no '67 Firebird left the factory with a 4.33 rear.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement
2006 Mustang V6 Pony, Vista Blue. Factory ordered.
2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it)
Old projects, gone but not forgotten:
1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it.
1980 Turbo Trans Am
1970 Mustang fastback, 351C 4Bbl, auto
1988 Mustang GT, 5 speed
1983 F-150 4x4, built 302
1994 Chevy K2500 HD 4x4, 454 TBI
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Joined: Jan 2012
Posts: 2
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Joined: Jan 2012
Posts: 2 |
the case does have the ears at the top. the casting # is 9788647. I found info in the F.A.Q.'s axles section about the 4.33 ratio only being installed in thirteen Firebirds in 67. the article says there should be a "YL" code stamp on the axle tube. does any know if this is an ink stamp or an imbossed stamp like on an engine?
Last edited by deans67; 01/14/12 01:29 AM.
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Joined: Dec 2011
Posts: 101
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Joined: Dec 2011
Posts: 101 |
It should be stamped into the axle tube.
Restoring a 1968 400 4spd, numbers matching Firebird Coupe, Verdoro Green. Larry  My old 68. Wish I had her back.
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Joined: Dec 2011
Posts: 101
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Joined: Dec 2011
Posts: 101 |
Axle code should be on the left (drivers) side of the axle housing about 6 inches give or take from diff. cover
Restoring a 1968 400 4spd, numbers matching Firebird Coupe, Verdoro Green. Larry My old 68. Wish I had her back.
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Joined: Jan 2002
Posts: 7,719
Power Member
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Power Member
Joined: Jan 2002
Posts: 7,719 |
Look near the welded on bracket for the brake pipe.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement
2006 Mustang V6 Pony, Vista Blue. Factory ordered.
2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it)
Old projects, gone but not forgotten:
1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it.
1980 Turbo Trans Am
1970 Mustang fastback, 351C 4Bbl, auto
1988 Mustang GT, 5 speed
1983 F-150 4x4, built 302
1994 Chevy K2500 HD 4x4, 454 TBI
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Joined: Aug 2007
Posts: 466
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Joined: Aug 2007
Posts: 466 |
Has anyone PHSed this car?
1969 Firebird 350 Coupe, Rust free Texas body, formerly brown, now a TA clone with quality spoiler, latching hood and TA wheel; 1969 GTO Convertible Expresso Brown/Parchment(currently painted red). Both numbers matching. My first love was a Cameo White 67 326 Coupe, bought back in 1983, at the age of 17, for $1,200. Been hooked since on PONTIAC! Working on a 67 400 ragtop for customization-Gulf Turquoise/Parchment/400/4 spd! My winter project!
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