Anyone know off the top of their head which diffs were available with the 2.45s? Was it just the 8 1/4", or did the 9 1/4" have them available as well?
Travis..

8 1/4 only I believe. I've never seen taller than 2.71 for a 9 1/4.

Thats been my experience as well.

Good to know, thanks guys.
Travis..

My 85 fifth ave had 2.36 gears. It was a 318 car. Don't know the rear end, just know that when the trans locked up at 45 MPH, it has zero power on any grade

Was reading the factory brochure for my 70 sport satellite - the 2.45 gear came in the highway package - 383, 2bbl, 8.25 rear geared with 2.45:1 ! I didn't know they did them back in 70.

I got a complete 8.25 rear end with 2.45 gears for my 74 Duster360. Put it in before driving to Carlisle back in 1999. Still in there today - get 22-23mpg @ 70mph ! The 360 has tons of torque to spin the tires ! Great way to have a driver !

Finally got a sure grip center section for the gears, and will get it installed later this year.

Mark

I have 2.76'a in my 8 1/4 rear too. It's nice being able to keep up easily on the hwy. But i've been trying to decide for over a year as to whether I want to add a suregrip to what I have, or swap out for a suregrip 8 3/4 with say 3.23 or 3.55 gears for a quicker start from a standstill.

I had a 1975 Duster that had an 8.25 that had the 2.45 gears,in an old D.C. manual it stated that the 2.45 was used with a special carrier because of the pinion being larger and in turn the ring gear was spaced further away than the other series carriers.

Good info guys. I know my sisters 318 5th ave had really big gears in it and was a complete slug I have a 2.76 sure-grip 8 3/4 in my GTX at the moment, but thought it might be cool to locate a 2.45 rear if one was available in a 9 1/4 variety. I can't imagine the 8 1/4 would live very long behind a 440/4 spd even if I treated it reasonably, so I guess it's not to be. The 2.76s should get the job done fairly well anyway.
Travis..

Better save money for clutches! The factory didn't put 2.45 or 2.76 gears with 4 speed cars because you have to slip the clutch so much to get the car moving.

I'm not worried about the clutch, I've got mad skilz yo!
Travis..

AND a free satellite hood.

Oh yes, that too
Travis..

Back when I was young and dumb I had a '69 383 4spd RoadRunner. One nite I trashed the 3.55's and all I had laying around was a set of 2.76's so in they went. With the tall 15" tires I was running it would do 105mph in second gear at the shift point. Even with some engine upgrades it didn't have enough power to get even half way through 4th gear. I'm lucky to be alive today after all the high speed runs I made in that car. Dave

^^Nice, that's what I like to hear. I just want good fast lane cruising ability and the ability to scare myself Living in the west, being able to cruise at 75mph or faster is a MUST.
Travis..

2.26 was available in the 8 1/4
2.45 in the 7 1/4

I have an 8.25 with a 2.45 sure grip. Also a bunch of 2.76 8.75s chunks. I had a 2.76 sure grip in my 68 cuda out of a c-body. I had a diplomat once that had 2.20 open 7.25.

I had an 8 1/4 rear with a 2.45 gear. Went and bought a sure grip for it found out like said above that I couldn't put with the 2.45's. Ended up getting some 2.76's for it. I couldn't even tell you where that rear end ended up. The last I seen it was welded up in a four link in a buggy behind a slow tie motor.