8 3/4 or Dana 60?

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

Moderator: Site Administrators

User avatar
redline337
Satellite Sebring (RH)
Posts: 70
Joined: Sun Mar 28, 2010 4:55 pm
My Cars: 71 Satellite Sebring RH

8 3/4 or Dana 60?

Post by redline337 » Sun Jun 19, 2011 9:42 am

I currently have a 8 1/4 rear end in my car, but I want to upgrade. My father-in-law has both a Dana 60 (with sway bar) and an 8 3/4 rear that he said will fit in my car (I know for sure the 8 3/4 will. it's out of a 74 RR, but I can't remember what car he said the Dana was out of). I'm leaning toward the 8 3/4 because changing gears will be easier if/when I swap in a big block, but I want everyone's opinions on this. I've had Dana 60s in trucks and never had problems. Are they stronger than the 8 3/4? Thanks!

User avatar
471Magnum
GTX (RS)
Posts: 534
Joined: Mon Dec 31, 2007 5:16 pm
Location: Evansville, IN

Re: 8 3/4 or Dana 60?

Post by 471Magnum » Sun Jun 19, 2011 11:05 am

You didn't mention what engine and transmission combination you plan to run, but a 8 3/4 can be assembled to handle anything you can dish out on a street car.

Dana 60 is inherently stronger, but gear swaps are more difficult and ratio selection is limited. Heavier too.
-Jim
"I can fix it... my old man is a television repairman... he's got the ULTIMATE set of tools... I can fix it."
Image

SureGrip
GTX (RS)
Posts: 143
Joined: Sat Mar 20, 2004 11:04 pm
My Cars: 71 SSP....lots of parts
Location: Central Md.

Re: 8 3/4 or Dana 60?

Post by SureGrip » Sun Jun 19, 2011 12:38 pm

If you are planning on building a RR/GTX clone and want to have it correct, go with the Dana...otherwise, use the 8 3/4 as mentioned above.

My '72 has a 9 1/4 that someone put in it, but also have an 8 3/4. I'm going to stick with the 9 1/4 and possibly have it upgraded by Moser as per the Mopar Action article.

my $.02
One day - 1971 Road Runner clone

User avatar
471Magnum
GTX (RS)
Posts: 534
Joined: Mon Dec 31, 2007 5:16 pm
Location: Evansville, IN

Re: 8 3/4 or Dana 60?

Post by 471Magnum » Sun Jun 19, 2011 12:48 pm

Regarding "correctness", the Dana 60 only came behind four speed equipped 440 and Hemi cars.

Another point to consider, passenger car Dana 60s are more expensive to obtain due to their relative rareness, but if you've already got one in your possession, it's a moot point.
-Jim
"I can fix it... my old man is a television repairman... he's got the ULTIMATE set of tools... I can fix it."
Image

User avatar
471Magnum
GTX (RS)
Posts: 534
Joined: Mon Dec 31, 2007 5:16 pm
Location: Evansville, IN

Re: 8 3/4 or Dana 60?

Post by 471Magnum » Sun Jun 19, 2011 12:54 pm

Take a close look at that Dana 60. Make sure it is a passenger car unit, easily identified by the pinion snubber mounting pad. Truck unit won't have this. Truck units generally have bigger axle tubes and are full-floating, not to mention being wider. They can be converted (and several guys specialize in this) but it's not cheap or easy.
-Jim
"I can fix it... my old man is a television repairman... he's got the ULTIMATE set of tools... I can fix it."
Image

SureGrip
GTX (RS)
Posts: 143
Joined: Sat Mar 20, 2004 11:04 pm
My Cars: 71 SSP....lots of parts
Location: Central Md.

Re: 8 3/4 or Dana 60?

Post by SureGrip » Sun Jun 19, 2011 2:56 pm

471Magnum wrote:Regarding "correctness", the Dana 60 only came behind four speed equipped 440 and Hemi cars.

Another point to consider, passenger car Dana 60s are more expensive to obtain due to their relative rareness, but if you've already got one in your possession, it's a moot point.
Good point...I should have clarified that.
One day - 1971 Road Runner clone

User avatar
redline337
Satellite Sebring (RH)
Posts: 70
Joined: Sun Mar 28, 2010 4:55 pm
My Cars: 71 Satellite Sebring RH

Re: 8 3/4 or Dana 60?

Post by redline337 » Sun Jun 19, 2011 6:05 pm

Thanks for all the info! I'll have to ask him again what that Dana came out of. I think he said it was out of a 77 Monaco cop car. If that's the case, and if I've done my research correctly, the spring perches will line up, but flange to flange the width is 1.4" wider. I'm thinking the 8 3/4 seems like the way to go. As far as what motor/tranny combo I end up with I'm not sure yet. For now I'm leaving the 318/904 in it. In the future I might put a 440/727 or if I win the lottery I might go for a 543 stroker. :wink:

71440 gtx
GTX (RS)
Posts: 1036
Joined: Tue Nov 25, 2003 2:34 am
My Cars: 71 gtx 71 340 duster
Location: I am here, or is it there? GIF image (animated, 49 frames)

Re: 8 3/4 or Dana 60?

Post by 71440 gtx » Sun Jun 19, 2011 6:09 pm

471Magnum wrote:Regarding "correctness", the Dana 60 only came behind four speed equipped 440 and Hemi cars.

Another point to consider, passenger car Dana 60s are more expensive to obtain due to their relative rareness, but if you've already got one in your possession, it's a moot point.
all 67- 72 440 4bbl 4 speed came with dana 60 354

69 1/2 440 6 bbl cars came 410 dana 60 auto or 4 speed they do not come with a 354 dana 60

on 69 -71 440 4bbl you can get 410 dana 60 auto
or a 410 on 4 speed :beer:
70-71 440 6bbl 410 dana 60 auto
71 gtx 440 4speed air grabber blue on blue with white vinyl roofOption cassette player


Plymouth's gonna getcha!
There are 3 things that will live forever, cockroaches, Keith Richards, & slant 6

User avatar
redline337
Satellite Sebring (RH)
Posts: 70
Joined: Sun Mar 28, 2010 4:55 pm
My Cars: 71 Satellite Sebring RH

Re: 8 3/4 or Dana 60?

Post by redline337 » Sun Jun 19, 2011 7:46 pm

71440 gtx wrote:
471Magnum wrote:Regarding "correctness", the Dana 60 only came behind four speed equipped 440 and Hemi cars.

Another point to consider, passenger car Dana 60s are more expensive to obtain due to their relative rareness, but if you've already got one in your possession, it's a moot point.
all 67- 72 440 4bbl 4 speed came with dana 60 354

69 1/2 440 6 bbl cars came 410 dana 60 auto or 4 speed they do not come with a 354 dana 60

on 69 -71 440 4bbl you can get 410 dana 60 auto
or a 410 on 4 speed :beer:
70-71 440 6bbl 410 dana 60 auto
Starting in 71 they are wider though, right?

I talked to my father-in-law and he said that rear is out of a Fury, so if it's a 75-78 it should be a b-body and therefore the right width?

User avatar
471Magnum
GTX (RS)
Posts: 534
Joined: Mon Dec 31, 2007 5:16 pm
Location: Evansville, IN

Re: 8 3/4 or Dana 60?

Post by 471Magnum » Sun Jun 19, 2011 7:51 pm

If it came out of a Fury, it's a 9 1/4, not a Dana.
Image

Image courtesy of Moparts.

Lots more info here:
http://www.moparts.org/Tech/Archive/axle.html
-Jim
"I can fix it... my old man is a television repairman... he's got the ULTIMATE set of tools... I can fix it."
Image

User avatar
redline337
Satellite Sebring (RH)
Posts: 70
Joined: Sun Mar 28, 2010 4:55 pm
My Cars: 71 Satellite Sebring RH

Re: 8 3/4 or Dana 60?

Post by redline337 » Mon Jun 20, 2011 7:45 pm

I found out it is out of a 77 Fury. So it must be a 9 1/4.

SureGrip
GTX (RS)
Posts: 143
Joined: Sat Mar 20, 2004 11:04 pm
My Cars: 71 SSP....lots of parts
Location: Central Md.

Re: 8 3/4 or Dana 60?

Post by SureGrip » Mon Jun 20, 2011 9:45 pm

redline337 wrote:I found out it is out of a 77 Fury. So it must be a 9 1/4.
I do 'believe' that the 9 1/4 has the same perch locations as the B-body...but they are roughly an inch narrower overall...which can allow for wider wheel options.
One day - 1971 Road Runner clone

gcoupe72
GTX (RS)
Posts: 147
Joined: Fri Mar 11, 2011 11:14 am
My Cars: 1972 Road Runner originally equipped as lemon twist,400,4spd,air grabber,performance axle pkg.,bk. interior.
Location: North Carolina

Re: 8 3/4 or Dana 60?

Post by gcoupe72 » Thu Jun 23, 2011 12:49 am

I've not seen this mentioned here, but weren't all factory Dana rears in '71-'72, actually the same width as '70-'71 e body rears, and therefor narrower than the 8 3/4?

Would love to hear from someone with a factory equipped Dana, who's measured it.
I'd think the extra tire clearance with aftermarket wheels, would be great.

71440 gtx
GTX (RS)
Posts: 1036
Joined: Tue Nov 25, 2003 2:34 am
My Cars: 71 gtx 71 340 duster
Location: I am here, or is it there? GIF image (animated, 49 frames)

Re: 8 3/4 or Dana 60?

Post by 71440 gtx » Thu Jun 23, 2011 8:34 am

gcoupe72 wrote:I've not seen this mentioned here, but weren't all factory Dana rears in '71-'72, actually the same width as '70-'71 e body rears, and therefor narrower than the 8 3/4?

Would love to hear from someone with a factory equipped Dana, who's measured it.
I'd think the extra tire clearance with aftermarket wheels, would be great.
my is 71 gtx factory equipped Dana 60 3.54 car :D

dana 60rear end widths, drum-to-drum:

'66-'67= 59 1/2" b=body
'68-'70= 60 1/8" b=body
'71-'72= 63" b=body
70 71 - 61 5/8" e=body
flange-to-flange 66-69 B-body 54-15/16" 70 B-body 54-29/32"
71-74 B-body 57-47/64"

70- 71 e-body 56 :beer:
71 gtx 440 4speed air grabber blue on blue with white vinyl roofOption cassette player


Plymouth's gonna getcha!
There are 3 things that will live forever, cockroaches, Keith Richards, & slant 6

gcoupe72
GTX (RS)
Posts: 147
Joined: Fri Mar 11, 2011 11:14 am
My Cars: 1972 Road Runner originally equipped as lemon twist,400,4spd,air grabber,performance axle pkg.,bk. interior.
Location: North Carolina

Re: 8 3/4 or Dana 60?

Post by gcoupe72 » Sat Jun 25, 2011 11:11 pm

So 71440GTX, have you actually measured drum-drum on your car?

Post Reply