What Do My 3rd Member Numbers Mean

[Lunchbox]

The previous owner put a posi unit in, not sure what it is, anyhelp 

[GoodysGotaCuda]

just tells you its a '741' case. wont tell you ratio or if it is a clutch or cone suregrip. What are you looking to find out?

(oh limited slip is "suregrip" unless your a chevy guy, then its a posi) 

[Lunchbox]

I thought maybe the 353 was the ratio. Othr then that all I was wondering if it was the right 3rd member for the car or year if you can tell that. Its a 1970 Chall.

[Chryco Psycho]

possibly if the car was a 318 or /6 originally , it is the lightest / weakest of the 3 carriers avaialbe

[moper]

The 8 3/4 would have had a small tag with the ratio on it, plus a series of paint daubs that are coded for different ratios. I'm sure the paint marks are gone, and if they pulled it to install the 'grip, then the tag was probably lost too. But, if it's a unit that is in good shape, you can jack up the rear and "count turns" to figure out what the gearing is.

[Lunchbox]

possibly if the car was a 318 or /6 originally , it is the lightest / weakest of the 3 carriers avaialbe

So if I have a 340 car this wouldn't be the right 3rd member for it. I have a feeling that the guy may have swaped the whole thing and that is what I am trying to figure out.

So the 741 case would have been for the /6 or the 318?? Sorry I am weak on my axle stuff.

[Lunchbox]

 

[Chryco Psycho]

looks to me like the carrier was swapped out at some point

[Lunchbox]

So what third member should I try to locate for my car? I am pretty much going back to stock on everything. I have found some good stuff on the net but I am no where educated on this stuff.

742?  489?   

[GoodysGotaCuda]

Are you going back to numbers and paint dabs? That 3rd member should run just fine. Just because it is the weakest out of the three, doesnt mean it is weak per-say 

We have 2 318 ebodys with original 489 cased 8 3/4s.....'splain that. 

[Lunchbox]

Are you going back to numbers and paint dabs? That 3rd member should run just fine. Just because it is the weakest out of the three, doesnt mean it is weak per-say 

We have 2 318 ebodys with original 489 cased 8 3/4s.....'splain that. 

I hear what you are saying but I have tried to keep the right numbers thus far and would like to keep it that way. So I probably should have a 489. I am looking for a you need this answer 

[Chryco Psycho]

they may have cuts costs & started using 1 carrier in 69 replacing both the 741 & 742 so it is very possible that 318 cars would have 489 

[GoodysGotaCuda]

I hear what you are saying but I have tried to keep the right numbers thus far and would like to keep it that way. So I probably should have a 489. I am looking for a you need this answer 

i just sold a 2.76 geared 489case for $60 today.