[MPR]

The NHRA rule book in Stock states; "Original rear end may be replaced with another from the same automobile manufacturer; truck rear end prohibited."

2009 and 2010 Drag Pak Challengers originally came with NO rear end so a racer of one of these cars isn't replacing the original rear end, simply installing it. The only rear end this automobile manufacturer ever spec'ed for a Drag Pak Challenger is in the Mopar parts system listed as part number P5155850.

Automobile manufacturers purchase most axle assemblies from suppliers like AAM and Dana. Mopar contracted Dana to build a Dana 60 for automobile use (NHRA prohibits the use of truck rear ends) and this was some 45 years ago. Mopar put a part number on it and used it in their muscle cars for a few years making it legal for use in NHRA Stock. Mopar never owned Dana Corp. and didn't manufacture the axle they just bought special Dana 60 rear axles from Dana and assigned a part number to it thus making it legal by NHRA.

Mopar part number P5155850 is the only part number Mopar list as a rear end for a Drag Pak. It is manufactured by an aftermarket automotive supplier and is in fact the original rear end spec'ed for a Drag Pak since NO rear end came in a 2009 or 2010 Drag Pak from Dodge. It is BTW the very same Strange Nine used in all of the factory hotrods being built today. Cobra Jet Mustang, COPO Camaro and yes, Drag Pak Challenger.

The P5155850 was put into the Mopar parts system in 2010 and anyone can check with Mopar or online to verify the info above. This Strange Nine rear axle has been approved by the NHRA for all 3 brands factory race cars. This is obvious when reading the 3rd paragraph in section 8-Stock in the NHRA Rule Book. "OEM may apply for inclusion of any special production runs into the Official NHRA Stock Car Classification Guide." If the NHRA didn't approve it then how did the Drag Pak make it into the Classification Guide? Call it a Nine Inch, call it an 8 & 4 quarters or call it a P5155850. I sure hope this clears things up!