couple bolt pattern questions

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Dusterdude72

Dusterdude72

IN MOPAR MUSCLE MAGAZINE
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I checked my bolt pattern on the duster and it looks like I have 4" all the way around.

I was thinking since it had an 8 3/4 out back that it was going to have LBP in back and SBP in front.

I was assuming this rear end was transplanted into the duster at some point in time because it has had a 3" inward spring relocation done and it has been built with 4.56 posi. its a 489 center section also.

I "think" some a-bodies came with 8 3/4 from the factory right? if so....how do I know if my 8 3/4 is factory to my duster?

also ,did the factory 8 3/4 rears in the dusters come SBP? or ?

I ran my fender tag to see if it said anything about rear end but I didnt come up with anything....is there any other way to tell?

here is what I gained from my fender tag.....not sure if all the numbers are correct because I jotted the numbers down over a year ago and can't remember if I got them all right but anyhow, here is the break down I got.

VL29:
Plymouth Valiant,Duster
Low
2 Door Sports Hardtop

G2B: 318 150HP(net) or 155HP(net) 1-2BBL 8 CYL
1972
Dodge Main, Hamtramck, MI, USA

350765: Sequence number

E44: 318 cid 2 barrel V8 230hp
D34: Light Duty Automatic Transmission
G11: Unknown Exterior Color
H51: Trim - High, Cloth/Vinyl Bucket Seats, Unknown Color
GY4: Gold Int. Door Frames
310: Build Date: March 10
566303: Order number

Y84: Unknown Top Color
EN2: End of Sales Codes
V4Y: Vinyl Canopy Roof, Gold
U: USA Specifications
A64: Unknown
B51: Power Brakes

M21: Roof drip rail moldings
N95: Emissions Control
R11: Radio Solid State AM (2 Watts)
V5X: Body Side Stripes, Black



Also ,is there any "rarity" to my duster having what options it has? ....I wouldnt think so but then again I never really asked before.
 
The fender tag will not show your rear gear. It's only on the build sheet and yes 8 3/4 was offered in SBP for your Duster.
 
all 340 dusters and some 318 duster would have had 8 3/4 rears installed..

all Duster 8 3/4 are SBP from the factory...

a 489 case would be the correct case for a 70-72 Duster...

as far as it being the original housing....have no clue as to tell it is or not

the original 489 case can have a spool and 4.56 installed...

the original housing can have new perches welded to move the springs inboard...
 
Thanks for chiming in.

I didnt mean since it has had new perchs welded on for spring relocation and the fact its 4.56 gears now means that it must not be a factory unit..... I was just saying since I knew that stuff had been done that it could be possible maybe someone put an 8 3/4 in it.

I was unsure what a-bodies came factory with 8 3/4 and what ones that did if they came with SBP or not.

thanks for clearing that up for me.
 
If I'm not mistaken, all A body 8.75's were SBP. After 73 (I think) your axle options were 7.25 or 8.25, both in BPB.
 
gilgalad1138 said:
Sweet. How are things down there? You get any tornados yesterday?
Click to expand...

not to shabby.

nope no tornados but for the passed couple days it has been WINDY...reallllly windy.

I live on a hill accross from part of a lake and the wind really gets kicking.

the sirens went off for a tornado but luckily there wasnt any here.

this summer we had a couple though
 
I would guess that sincwe your car is a 318 car, it probably started life with a 7 1/4" rear, and the 8 3/4" was transplanted later. No worries though, since you have small bolt pattern axles, I would guess that it is an original A body unit. Moving the spring perches is a common mod when moving the springs inward with the spring location kit for fatter rubber out back. It being a 4:56, I'm-a-guessin' there was some track time scheduled for your car before you got it!!! Geof
 
just because it came it a 318...does not mean it came with a 8.25...

my 71 318 with 904 came with a 8 3/4 from factory...
 
cosgig said:
I would guess that sincwe your car is a 318 car, it probably started life with a 7 1/4" rear, and the 8 3/4" was transplanted later. No worries though, since you have small bolt pattern axles, I would guess that it is an original A body unit. Moving the spring perches is a common mod when moving the springs inward with the spring location kit for fatter rubber out back. It being a 4:56, I'm-a-guessin' there was some track time scheduled for your car before you got it!!! Geof
Click to expand...

I know it had track time on it.

the kid I got it from had the 360 that he took out of it, he offered it to me when I bought the duster....The duster I picked up for $500.00 but he wanted $5,000.00 for the engine LOL.

wasnt in the budget.

anyhow I was told by a few folks I know that knew the car that the car use to pull wheelies and there was a 10 inch of so OUTWARD crease in the drivers side quarter panel which leads me to believe that it seen some hard launchs....and no subframe connectors on it either lol.

Im leaning towards believing its the factory rear end the had been beefed up ( I found out that our local well known race transmission builder who also does other drive train work was the one that built the rear end in it.

so atleast I know it was built right and should hold up well.
 
If in '72, you ordered a suregrip, you got an 8 3/4", and also a larger radiator as a package. And yes, the 8 1/4" rearend wasn't used until '73, and '72 was the last year
for SBP.
 
Jerrod, have you looked for the buildsheet under the backseat of your car?? Either in the springs of the rear seat bottom or in the springs of the seatback?? That would go a long way to determine what your car came with!!! By the way, I never said it couldn't come with a 8 3/4", I just said it probably didn't!!! You'll never know unless you find that buildsheet!!! Geof
 
As already stated the 8 3/4 rear that came in A-body cars was always SBP. I pulled a 8 3/4 rear out of a '71 Dart Swinger Special before, it was factory installed and the car was a 318 auto. I have also seen a 70 Duster slant 6 3 spd. manual with factory 8 3/4. A lot of manual trans. cars got them.
 
cosgig said:
Jerrod, have you looked for the buildsheet under the backseat of your car?? Either in the springs of the rear seat bottom or in the springs of the seatback?? That would go a long way to determine what your car came with!!! By the way, I never said it couldn't come with a 8 3/4", I just said it probably didn't!!! You'll never know unless you find that buildsheet!!! Geof
Click to expand...


I tore this car APART!!! last winter looking for a build sheet lol.

someone already had there grubby little hands in the car before i got it and must have yanked them all out.

carpet was trashed and had been soaked and mice had been in it....so if it was there than it has been long gone for awhile.

nothing under the bench seat, nothing under the bottom or back of the back seat.

nothing under the head liner

the glove box liner was missing so if there was one there its long gone.


I guess Ill never really know for sure all the facts about the car from when it was factory but ohh well.

its not like its a numbers matching 340 car with some ultra rare options and I am not building it back to factory specs....it would just be interesting to know some of the things is all.

and it is a sure grip 8 3/4 and being a 489 center and being SBP it sounds liek it just might be the factory rear and someone did some upgrades too it is all.

who knows? lol

thanks to all who have chimed in with info though, I appreciate it
 
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