I have a '69 442 with a type O rearend and 3.91 gears. The engine is a mild 455 that will see an upgrade in the future. I'd like to hear if anyone out there is "beating" on the type O 10 8.5 10 bolt and having issues? What can a guy expect out of the type O once it is behind some serious torque (600 ft lb) and sticky rubber? I know some parts are getting hard to find for the type O. What have people been swapping in the place of a type O? Currie Manufacturing 9" or 12 bolts? Strange Engineering?

Thanks for your input.
V/R
Joel C

 

A local racer here in Calgary does 11.4s @ 116.5 mph in his 68 442 with a Type O and 3.91 gears. No problem behind his 455, T400 and 255 60 15 drag radials.

 

If money is NOT an issue (which with muscle cars is now just the normal)
Why destroy a original 3.91 GM rear that a restorer would love to have under there car.
IF you have the Money a 12 bolt Chevy with 33 spline axles and Ford nine large axle bearing 7900 billet end for GM drum brakes... This way you can go full spool if you just want to race or a 33 spline posi eaton or true trac or auburn are all available and the rear will still resemble a original option.

Just my opinion... Jim
J D

 

I agree with much of what you said Jim. I'm not a restoration purist. It's not important to me that I have a type O rearend, only that I have one that holds up. I would change the rearend before destroying it and sell it to someone that requires it for their restoration. I won't say that money is not an issue but I can work to afford something that will hold up. I won't go full spool or mini spool. I just wish I'd hear more from others that have switched and what they are using (Currie/Strange....ETC?) I've ran an Auburn posi in my '82 GMC...love it. No complaints.

Thanks
Joel C