OK, the research I did on Team Chevelle indicates this SHOULD be an early 1972 8.2 axle. The 69277 matches a Chevelle 10 bolt but is missing the 39 prefix ?
The H51 is a casting date code of August 5th 1971 for a 72 application.
The GFC 259 2W breaks down like this; GF=3.08 ratio. C = Buffalo NY assembly plant, 259 is the 259th day of 1971 = Thursday, Sept 16th build date. 2 is second shift and I haven't found any reference to the W. Width info is below.
1964-67 Chevelle rear ends were manufactured by the Chevrolet Gear and Axle Division. The housing measures 53.25 inches from backing plate to backing plate and with the brake drums in place, the total width is 60.00 inches. Axle tube flange-to-flange is 54.25 inches.
* 1968-72 Chevelle rear end housings measure 58.5 inches from flange to flange, and with the brake drums in place, the total width is 62.5 inches. (Note: Other sources put the total width at 61.125" to 61.25".) Axle tube flange-to-flange is 55.25 inches.
* A second measurement to check is centerline distance between spring perch seats. 1964-1967 are 35 1/16 inches between seats where 1968-1972 are 34 31/32 inches.
If you pull the cover and it has spring and clutch posi, it has been put in after manufacture. If it has cone posi, I'm lost ....
1967 GTO; Gulf Turquoise on Black, 4 speed, buckets SOLD
1967 Camaro ss/rs 350
1966 Chevelle SS 396
1966 Chevelle Malibu
1970 Chevelle SS 396
1962 Impala SS
1952 Chev 2 ton flat bed
1938 Chev coupe