1974 Duster - What rear axle do I have, 7 1/4 ???

[DaWeezzz!!!]

Greetings,

I think I know what rear axle I have on my 1974 Duster. Just wanted to confirm with all you experts. Will this be ok with a 1973 340 and a 904 Transmission? Thanks... ALEC!

 

[Mtrhead]

Can't see the top of the differential if you have 9 bolts on the plate it's junk if you have 10 bolts on the plate it's good 8.25 rear is pretty strong @ least for a small block on street...

 

[halifaxhops]

Looks like a 7.25 to me get at least a 8.25. A 7.25 will blow up on you with a 340.

 

[72Dinger]

7.25" - clean the crud off the head of the bottom-most cover bolt and and there will be a gear ratio tag, likely 2.76.

 

[H22A4]

There isn’t the need to rush out and find a 8 1/4 before you drive an inch with the 340 in front of it. Is the 8 1/4 a stronger long term choice? Absolutely. However, the 7 1/4 isn’t going to blow up as soon as you move the gear selector into Drive. If you’re doing smokey burnouts at every intersection then that 7 1/4 is going fail sooner than later but it’s entirely possible to drive with a 7 1/4 and a 340.