8 1/4 Rear End Bolt Pattern

[Nick96]

Hey guys,

I'm in talks with a guy on an online classifieds site that's selling an 8 1/4 Rear end. The rear end is from a 1970s (year unspecified) Duster 340. Is there any way to know (without driving out to him and measuring) whether the axles will be 5x4 or 5x4.5? My goal is to upgrade the rear end from the 7 1/4 in my 68 Valiant to accommodate the mild 360 (300-350 HP) that will be going in this spring.

Not looking for people to just dog-pile on telling me to get a 8.75 (this isn't for the strip, just cruising), just want to know about the axles.

Thanks guys!

 

[halifaxhops]

Can the guy use a ruler? pretty simple, and the 8 1/4 is a misunderstood rear IMO.

 

[65 Dartman]

If it's an 8.25 it will be 5 on 4.5

 

[Lee Robinson]

If it's an 8.25 it will be 5 on 4.5

I believe 73-76 in A bodies, and were all 5 X 4.5 bolt pattern. A very adequate diff, unless a high horsepower
application is used. These usually came in cars with front disc brakes.

 

[rumblefish360]

I believe 73-76 in A bodies, and were all 5 X 4.5 bolt pattern. A very adequate diff, unless a high horsepower
application is used. These usually came in cars with front disc brakes.

What is high horse power?

 

[440plus6]

If it's an 8 1/4 from a 340 duster, it is most likely 73 or later. As far as I know, pre 73 340 cars used the 8 3/4. If it is 73 or later it will be 5 x 4 1/2 (bbp).

 

[halifaxhops]

What is high horse power?

I am running almost 500 on mine so far so good just a trak lok in it.

 

[xLURKxDOGx]

What is high horse power?

1600-1800.

Jake

 

[rumblefish360]

DANA 60 or Pro Ford 9 by then!