Gentlemen,

I will soon be shopping for a 38-47 Olds. I have a 350 Olds engine out of my 1973 Cutlass that I hope to install. I would appreciate any thoughts as to whether or not the stock rear end for any of these years would hold up.
I cannot stress strong enough that my "hot rod" days are long gone, and would take it pretty darned easy on the drivetrain. The 350 will be pretty stock, 8.5 compression, rated at 180hp back in the day. My understanding is that the rear gear for most of this range of cars varies from 3.90 to 4.10, so I would be using an overdrive trans for interstate cruising.
Strong enough ?

 

I would be afraid of axle failures, they are not very strong.

 

Looks like 10 or 16 spline axles, which won't be strong. It may hold without burn outs.

 

I'm not positive but that might have a torque tube driveshaft. If so, you will have to replace it. I would go with a Ford 9 inch with redrilled axles for 5 X 4.75 bolt pattern.

 

Here is the problem I see with any rear older than 1955.
first PARTS....You just are going to have a hard time finding any internal parts if you ever need them
2nd... the age of the rear is already against you and probably NEEDS parts already no matter how low mileage.
3rd... if you are driving this car freeway speeds etc are going to be higher and longer runs than a older rear is use to. reason those cars had high steep gears is 1) the motor was poor on power output. 2) the wagon wheels were tall. 3) they just plan did not go anywhere they hung around a city most of the time...

Strength of the rear - for what your doing they probably would make it ok. It really depends on the resto your going to do. If all out resto is what you are after and things have to look and be original then you have to keep that rear. BUT since your already doing a 350 in the vehicle and overdrive I would up date the rear. and drive shaft... does not necessarily mean new and heavy duty but something you can get parts for when (yes things will go bad sooner or later) you need to repair them.

Hope this helps in your decision and again I ALWAYS tell everyone this....'THIS IS your resto you can build your vehicle how ever you want' Have fun and enjoy.

Jim
J D

 

Many thanks to all that replied to my question about rear end strength.

The additional points made about the difficulty of getting parts, the fact that the rear end was not intended for sustained running at 70 etc. make me realize it is probably too risky.