95 caprice rear diff

wich rear diff is better 3.08 3.23

The 3.23 will offer better acceleration and responsiveness at the expense of top speed and fuel economy.

You are only half right. 3.23s will actually INCREASE top speed because these cars in stock form are wind resistance limited before the engine is up to peak power rpm. By letting the engine get closer to peak power rpm you can actually go FASTER with even say 3.42.

3.73s would be close to limiting top speed based on rpm rather than air resistance.

Basically to hurt to-p speed you would have to go to 3.90-4.10 or beyond.

Let's put this in perspective a little 5000rpms in OD with 3.08s would be over 180mph do you honestly think the engine has the power for that???

Reality is the wind stops acceleration usually 145-150mph at which point the engine is little over 4000rpms, well below peak HP number. Something like 3.42 lets the engine reach closer to peak HP

^^ Well said.

If the car has an overdrive 4 speed transmission, the 3:23 is the better choice.

The 3:08 is only beneficial for a slight gain in fuel economy. It's worse for all other considerations.

FWIW I only prefer 3:08 or taller rear ends in cars which have old 3 speed auto transmission.

thank you guys very much

Personally I like 3.42 for a mileage car. Did just as well as the 2.93s it came with or the 2.56s in the wagon, actually for normal rural and in town driving the 3.42s are better mileage than the 2.56s. Whomever decided 2.56s in a 4500lbs+ car with OD and lockup was a good idea needs a swift kick in the seat.