I have added a housing and axle calculator that will help you determine the specs of Mopar 8 3/4″, Dana 60, and Ford 9″ rearends.  If you know the housing measurements, it will calculate the axle lengths.  Likewise, if you have existing axles and want to build a housing around them, enter the axle dimensions and it will derive the housing measurements.

The calculator assumes DoctorDiff standard “brake gap” by default, although this can be overridden.  Mopar-spec brakes will work with the default values, but anything else should be verified.  If the brake gap is too narrow for your brakes, they will not fit.

If you are re-using an existing housing, verify that all calculated values match your housing’s measurements!  If they don’t, you have entered something wrong or your chosen brake gap will not work!

Try it out!

Coverage of Popular Hot Rodding’s 2013 Muscle Car of the Year has been posted on their website.  There were two Mopars competing: Kevin Wesley’s 1970 Satellite and Eric Wracker’s 1971 Duster.  Both cars ran DoctorDiff “Cobra-style” rear brakes.  The Satellite ran a DoctorDiff 8 3/4″ housing and axles, and the Duster ran an 8 3/4″ ring and pinion supplied by DoctorDiff.

Congratulations to both!

Check out the coverage here.

The December 2013 issue of Chrysler Power Magazine includes an article featuring a DoctorDiff 489 case 8 3/4″ third member and bearing and seal kit.  See the article on page 45 titled “Screaming Yellow Zonker”  by Scott Smith.

Check it out on newsstands now!

Please note that although the article refers to drdiff.com, the correct address is doctordiff.com.

I will be attending the SEMA Show in Las Vegas from Monday, November 4th through Friday the 8th.  I will be back in the office on Monday, November 11th.