I found a full axle for sale with 355 gears. Is this posi? And if so, is it a good rear, should I buy it? I have the stock RS non posi rear whatever that may be right now.

 

gear ratio doesn't have anything to do with what kind of carrier it may have, or not have. it seems you're a bit confused about terms, an axle is a shaft that connects the carreir to the wheel. the easiest thing to do would be to look at it and see if it's a posi or not. might help too if you said what you have or what sort of rear you're looking at.

 

3.55 ? what is the axle from ? what model is it ? sounds like an old 10 or 12 bolt from a chevelle or something similar, they commonly were 3.55 late 60s early 70s

pull the diff cover to make sure of whats in it, for all you know it may be broken, who knows
never buy an axle without opening it up and closely inspecting, same with transmissions, and evne engines whenever possible



good luck

 

It's probably a ford 8.8 rear end. The 3.55 gear ratio was very common in those.

 

ok

i dont know on that one, ive only been inside of one 8.8 and it was under an 82 ford f150 pickup, it chucked the gears, so we put an old 9" under it

 

The 9" also has some, but it's hard to find a stock 9" with 3.55 gears in the first place.

 

I don't believe that ratio (39:11) exists in a 7½" 10-bolt.

It's pretty common in some other rears; Chrysler 9¼" for example, or the "classic" rears.

Ratio has nothing to do with whether it has a posi carrier or not.

 

after much thinkign and finally remembering, its the 3.50 ratio thats commmonly found in the old 9" axles, 70s older

other than 4.10 or so under the old F-100 pickups

i need to get a couple more soon, one needs to go under my 84 c-10 so i can rid of the crap 8.5" and 2.73

i could have it all welded in place in about an hour or so afte ri go get new leaf spring perch mounts for the axle tubes they are inexpensive


thanks

 

Im glad you all are as clueless as I am. I had never heard of the ratio in concern to Fbodies, the women at the junkyard told me that this rear was being pulled off of a 1992 camaro RS, thats why I assumed it was a stock rear. Could she have possibly been mistaken with 3.42?

 

if its the stock rear, 2.73 auto, 3.08 manual. the only way to be sure is to count the teeth and do the math, dont pay for anything until they pull the cover for you.

41-15 2.73
40-13 3.08
42-13 3.23
41-12 3.42
41-11 3.73
41-10 4.11
41-9 4.56

 

That's only if it's a 305.

If it's a 6-cyl, it may have a better ratio. Some of the 6-cyl 5-speed those came with 3.42s.