Can someone tell me what this housing may have came from? Looks different from the ones in my 66 and 65 Tbirds measures 3 1/4 diameter on narrow section.

 

From what I can see it looks like possibly a truck nine inch. Looks flat on the bottom like it was shaved, maybe I am just seeing it wrong... Look for a tag, if it is there it will have a number like WGN... that will help determine what line it was intended for.

Paul

 

LOL... and I thought it was a 8.8"... Can you get a socket on the bottom two bolts...

 

I thought it is a 8.8"... It's looks like you can put a socket on the bottom two bolts... If you can it's a 8.8"

 

8.8" introduced 1983, has an inspection cover. If this axle does not have one (it doesn't appear to), post a dead on pic of the carrier.

1966 Thunderbird's w/a 428 came with a 9" that has a 9 3/8" ring gear. This rear axle was used in some T-Bird's, all Lincoln's and some other Passenger Cars thru 1972 and was an option on 1968/72 F100's.

The raised upper boss line on the 9 3/8's carrier has a distinct downturn on one end (left-drivers-side as I recall), whereas the 9" goes straight across.

Note inre to axle shafts: 9's installed in 1957/83 F100's, 1975/86 F150's, 1966/86 Bronco's and 1969/86 Econolines use the same axleshafts right and left, while Passenger Cars use specific right/left axle shafts.

The 9 and 9 3/8's rear axle ID tag was located at circa 5 o'clock and was under one of the bolts that retain the carrier (aka pumpkin) to the housing. Today, many are missing.

B7A-4035-A .. Housing Gasket / Use with 9" & 9 3/8" rear axles / (10) 27/64" diameter mounting holes / Fits: 1957/86.

The 9 3/8 inch shares only 5 parts with the 9 inch: Housing gasket, pinion seal, one pinion bearing and race, pilot bearing retainer.

EVERYTHING else is different including the axle seals, and there were two specific types of these used on 9 3/8's.