Rear Axle Question

[jimjim]

What is the difference between a 69 ( A L ) and a (A T) .They are both 3.08 gears.I know the (A T) has bolts and caps on the axles instead of u-bolts.What makes the difference between a regular and a HD rear end-besides the axles?

 

[GeoMac]

Here's my understanding ... while both are, as you noted, 3.08:1 ratios, the AL was used in 1969 for SB applications with Posi rear end. Also used in 1969 the AT was used in BB with Posi.

The HD indicates the type of universal joint caps used on the axle outputs of the differential. Labeled HD have block type caps and through bolts.

Does that help? Can anyone else weigh-in on this one?

 

[Artsvette73]

Here's my understanding ... while both are, as you noted, 3.08:1 ratios, the AL was used in 1969 for SB applications with Posi rear end. Also used in 1969 the AT was used in BB with Posi.

The HD indicates the type of universal joint caps used on the axle outputs of the differential. Labeled HD have block type caps and through bolts.

Does that help? Can anyone else weigh-in on this one?

AL smallblock
AT HD 427

 

[GeoMac]

JimJim,

I just re-read your post and I apologize. All I did was confirm what you already know. Sorry.

 

[Vettehead Mikey]

What makes the difference between a regular and a HD rear end-besides the axles?

nothing.