8.25 8 1/4 education needed

[dodge71demon]

Ok I have a 75 a body 8 1/4 stock open carrier rear end gear ratio unknown probably 2 something.Looking at a used set of 3:55's.Need educated on what fits what.Seems like I've seen that depending on the carrier is what gear ratio will fit on it and that you can alter one to accept different gear ratios if so how?Are the splines different on the pinion gear from early to later years

 

[scamp360]

I believe the carrier cut off is 2:56. any thing above will fit taller gears.

 

[daliant]

Some info on 8.25 rears

Carriers:
73-75: uses small carrier bearings
75-up: uses larger carrier bearings
Carriers are interchangable from73-96 as long as correct bearings are used

Ring and pinion ratios: 2.21, 2.47, and 2.56 uses its own dedicated carrier which cannot be used with numerically higher ring and pinion

Axles:
73-96 uses 27 spline axles
96- up uses 29 spline axles
All A body axles are 27 spline

Ring and pinion gears:
Interchangable from 73-04 as long as correct carrier for ratio is used.

 

[cudamark]

Ok I have a 75 a body 8 1/4 stock open carrier rear end gear ratio unknown probably 2 something.Looking at a used set of 3:55's.Need educated on what fits what.Seems like I've seen that depending on the carrier is what gear ratio will fit on it and that you can alter one to accept different gear ratios if so how?Are the splines different on the pinion gear from early to later years

If you're going to 3.55's, you'll probably want a sure grip anyway so just get the gears and carrier as a set.