Gears & Axles - axle ?

can someone tell me are the axle lengths the same if i had a 12 bolt axle compared to a 9 inch axle thanks for the response in advance.

I understand the question, but it seems like pointless information.
Can you be more clear on what you're doing so maybe it makes sense.

Side to side they are different lengths....meaning DS is not the same length as PS...that being said, I believe they are the same from a 12 bolt to a 9 inch assuming of course the rearend is of stock length.

The answer is no. A 12 bolt would have equal length axles 31 5/8" and a 1/2" pinion offset. The nine inch would have one axle longer than 31 5/8" and one shorter. I would give you the exact measurements for a nine inch if you give me the pinion offset. Typically with a stock style nine inch in an F-Body you would have a 15/16" pinion offset resulting in axle lengths of 32 7/8" and 30 3/8". This is assuming both have a friction disc style positraction unit. If the rears in question have Trutrack diffs. the size would change for the nine inch. If you have more specifics and PM with the details I will figure the correct sizes for you. All of this is based on the assumption that both rears have a housing end to housing end measurement of 59 1/4" and are using the stock brakes from the F-Body car.

A follow up on my previous post. There is also the issue of spline count on the axles. The only time the two rears will use the same spline count is if you are using a 33 or 35 spline spool. Which would change the axle lengths to some degree. Still the two would not interchange. I hope my reply sheds some light on your question.

thanks you answered my ?