73aussie455

I'm trying to identify all the bits on my '73 delta and have drawn a blank IDing the diff. I've looked at the tech pages but can't find any info that relates to my '73 Olds.

The codes stamped on the diff (location found on the tech pages) are;

KA B283 1

the diff has a 10 bolt rear cover.

If possible I'd like to find out the size, type, gear ratios and whether or not its a posi diff. ( I dont think it is but hey, you never know!)

Can someone help? Thanks for your replies.

copper128

If it's a factory 455 car, it's likely a P-type 8-7/8" (10-bolt cover/12-bolt ring gear)

If the car came with a 350, it might be a corparate 8-1/2" 10-bolt.

Pics would make an ID easier.

copper128

OK, looking at the codes in the 73 service manual (sect 4B-33), there is no KA code shown for a Delta 88.
However I'm gonna take a stab at this and say what you have is probably a 2.73:1 open 8-1/2" 10-bolt.
I'm guessing the K indicates an open diff 8-1/2" 10-bolt
the A in the 2nd position is consistent with a 2.73 ratio in all differentials used in the larger cars

copper128

Here's a link to a scan of the differential ID page from the service manual:
http://tinypic.com/m/i2t0nn/4

copper128

Was this car produced in the US for export?
If so, that could explain the discrepancy. The FSM may not have all information relevant to cars produced for non-US markets.

73aussie455

Thanks copper128.
It's a factory 455, TH400 produced in Lansing may '73 for the US market. Imported into Oz 2002.
I'll try to get some pics today.

Kennybill

Just from my experience, two 1971 Delta 88's both 455 v2, each had the 8 1/2 corporate. One 1971ninety-eight but it was a 455 v4, it had the larger 8 7/8 gears. Was it because the 98 was heavier or the 4 barrel? Ken

73aussie455

Thanks Kennybill for the info. How do I tell if its a v2 or v4 455 and whats the difference? It has the 4 barrel carburetor option.

Here are the diff pics. The last one came out reversed for some reason.

P091801_12-02-14_zps80360eda.jpg
P0916_12-02-14_zps34ed2a7d.jpg
P091802_12-02-14_zps0e173f99.jpg

copper128

Thanks for the pics.
As I suspected, the squared-off lugs underneath and the 2 parallel ribs on the side of the housing positively ID it as a corporate 8.5" 10-bolt.

And 4-bbl carburetor means exactly the same as 4v carb. The "v" is an abbreviation for "venturi".

73aussie455

Thanks for that info, again a great forum to be part of.
Nothing special then, just a run of the mill 8.5" 10-bolt 2.73 ratio diff.

Kennybill

Maybe just the "heavier" cars (98's) got the larger 8 7/8 rearend. Was your a factory 4 barrel 455? Actually your lucky because different gear ratios are available for your rearend. The bigger one not so much. Ken

73aussie455

I can't imagine a heavier car than my tectonic plate...
Yes it is a factory 455 4bbl