i have a guy that is will to sell me a 8 3/4 3.91 posi rear end from a 64 a100 van what i am wondering if it will fit on my 74 duster thanks for the help

You could always have it narrowed for around $150 or so. Sometimes it's easiar to cut to length. But then again, you would have to order custom length axles. ($350 or so).

If it is anything under $350.00, get it just for the 3.91 Sure Grip.
The Van's housing and axles are not anywhere close to what you need for your A-Body.
DD

350.00 is a great price for the pig alone. should be a 741 case with a V ramp sure grip. Go for it........

I have seen elsewhere, that a 741 isn't very strong. Is this fiction or fact?

bwhitejr

_________________
'72 Duster (Performance 360)
'83 Ramcharger (Performance 318)
'80 TrailDuster (360)
'80 D-150 Truck (See Below)
CompCams 252S, Holley 390cfm, Offy manifold
Ported, Polished and Gasket Matched
P4286813 Springs,0.040 Overbore,
0.090 Shaved Head

The 741 is fine behind the mild hauling truck, slant six, 318 poly, 383-2v etc... where this myth started was the crowd that would pull a 30 year old open 741 diff and plant a 1000+ hp blown hemi in front of it and have it whither on the bark of the tires...

3.91 sure grip 741 is about $350 at the Oregon swap meets, the hard part will be finding an A or B -body 8 3/4 housing and axles...

-D.Idiot

I run a 741 case with 4.30 gears in a 13 second Dart 2900 lbs for 5years now. Also run one in a 65 Belvedere 11 seconds 3600 lbs for 3years
741 get a bad rap because of the 3 cases it has the smallest pinion size 1 5/8 inch. 742 case 1 3/4 inch. 489 case 1 7/8 inch. I think that is correct sizes but don't quote me on it. Should live behind a slanter...

As DD says,

I would jump on it for the pig alone at that price. I got a 489 case pig for what I thought was a good price, rebuilt .....$550.00, good for "down south" Before installing it I ran a non posi 3.91 in a 741 case in my truck for 30 years without a hint of problem. Just wanted the posi and the 489. Obsession, ya know.

rock
'64d100