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?
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
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?
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
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!