So what would be the easiest way to change my rear to either 3.43 posi disc or 3.73 posi disc? I know how to pull the rear from the car but is there specifics i should stay with? like 9 bolt or 10 bolt and whats the diff in 9,10 and 12?

 

9 bolt was the borg warner rear

10 bolt is the 7.5 and 7.625

12 bolt never came in these cars and was gone after '72 in cars and '80 in trucks

there was a dana 44 under a few of these cars i have heard

a direct fit axle- from a third or fourth gen f body is what to use

3.42 and 3.73 posi are common under these cars, especially in the 84 85 86 years, see them all the time

good luck

 

How do i tell if i get an axle at a junk yard, ya turn a tire and if the other side goes same way its a posi, what about gears?

 

The only way to know what's inside it, whether you're worried about posi or gears, is to take the cover off and actually look.

 

Thats the only way to check the gears???

 

The only way to check with any certainty.

You might also want to know additional trivial little details like are the gears damaged at all, which you'll only find out if you actually look inside.

 

here's how to tell:
1)rotate the wheel one full turn (use the valve stem as a guide)
2)count the turns of the pinion or driveshaft
3)if the driveshaft turns 3-1/4 turns it's a 3.25:1 rear
3-3/4 turns- 3.73
2-3/4 -probably the 2.79
3-1/2 - probably the 3.42 (or if it's the 9 bolt - 3.45)
etc, etc.

 

Yeah, but you're still buying a pig in a poke. You don't know if you're buying a bunch of broken teeth and shavings.

 

Dana 44 was an over the counter deal, unless you bought a Firehawk from SLP.

The 9-bolt is the strongest of the 3rdgen rear ends (rare Danas aside) but are still far from bulletproof. The 10-bolt would be a better choice, because they are much easier to find parts for than the 9-bolt, and the 9-bolt isn't stronger by a whole lot.

 

First off... How much $ are you looking at spending? Lets start at square one.

 

Just looking at grabbing one from a junk yard!

 

you always have the option of gutting yours out and putting a posi carrier and new gears in. that way you'll know exactly what you have. i know its obvious but its always an option

 

i got a factory 10 bolt 3:73 at the shop with disc brakes mounts if your interested e-mail me and i`ll let you know if my partner hasn`t sold it and how much it will be

 

if you are looking at jusnkyard prices, then stick to the yards and hope for the best. If you are not gonna open it up and see what you get, then there is not much anyone can do for you. Just dive in an cross your fingers.... or you could just open it up...

The next best thing would be new gears, but then istalling them would run you some more $....

Let us know what you end up goin' with.

 

You also have different size carriers

 

goin to look at junk yard tomorrow and checkin if anyone has a cheap one here

 

it is a posi and i need $500.00 plus shipping i pm`ed you

 

$500 for a 10 bolt. that's insane. I wouldn't pay more than $200 for one of these rearends ever.

 

this is a 3:73 rear end posi hard to find from what i understand and this rear caomes with rotors and caliber just needs refreshing up

 

found crap at junk yard and for 500,no.

 

so did almost every Z28 or T/A from 84-87 that was carb'd, most 5 speeds got this rear end too. In fact the 9 bolts which were posi and had disc brakes don't even go for more than $400 TOPS and those are much stronger than the 10 bolt ever could be. Swap out the price to $200 and it might sell. 4th gen rear ends with bigger brakes on them only go for $250 all day.