mopar rear axle
 

Hello,
what are you using for rear axle assy for L M/SA? 4000lb car, will a 8 1/4 work? c-clip? 4:88's ? I can deal with changing ring/pinion each season just don't want to spit pinion out on starting line
building 1975 cordoba 400 4V for L/M
thanks gary

Re: mopar rear axle
 

Moser 8 3/4
Drop out center section. Will hold up for a long time.

Re: mopar rear axle
 

I run a N/O/P Mopar
@ 3500 to 3700 Lbs.
I would strong recommend to 8 3/4
The 8 1/4 is had to find gears for and
really much weaker!

Even in the Mid 70's Larry Shepard at the Mopar
Performance Seminars strong recommended losing
the 8 1/4
He stated that Mopar save a little over a single dollar
when they replaced the 8 3/4 with the 8 1/4. I guess
every dollar counted with a Mfg. that was bleeding money
at that time!

Re: mopar rear axle
 

My boy runs a 400 Roadrunner usually in I/SA at around 3700 Lbs

We have broken several expensive 8 3/4 third members before we went

to a Dana 60.

Re: mopar rear axle
 

It's the weight you should go by,Heavy = Dana
Based on my observations a 283 in a heavy Car could be thougher on rears than a 396/427 in a lighter car.
Trying to move a lot of weight from standstill in a hurry is what takes a toll on stuff.

My experience with 8 3/4 is that they start breakin up around 3500 pounds and even earlier if you have some serious power.
Then some say the Dana is faster also...sorry about the rambling,your question was about the 8 1/4 and 8 3/4 and I have zero experience with the first one!

Re: mopar rear axle
 

My experience is with the length. Axle tube flex caused most of the failure.

Re: mopar rear axle
 

My personal experience was that the extra performance of the Dana 60 made up for it's increased weight. The car did not slow down a bit. That seems to be most folks experience. If you can take out ballast to make up for the increased weight folks report the car picking up.

Of course changing the ratio in a Dana is a much bigger deal than a 8 3/4.

Your mileage may vary.

Bill

Re: mopar rear axle
 

GTX john hit the nail on the head D60 it is:)

Re: mopar rear axle
 

Dana 60 is faster and more cost effective. First ring and pinion lasted 19 plus years in the CUDA from 3800 lbs in C/SA to A/SA at 3200 lbs. Ask Chuck Beach with his 340 car.

Re: mopar rear axle
 

Dana 60, set it and forget it.