While not particularly known for its strength, the ubiquitous 8.25-inchrearend found its way under a whole slew of cars and trucks. Definitelynot as sexy as the 83/4, a drop-in-style differential featuring theconvenience of easy gear swaps or the nuclear bomb-proof Dana 60, butthis Salisbury-style differential is plentiful and reasonably strongwhen healthy. In a perfect world each and every one of us could affordto replace that modest 81/4 with one of Ma Mopar's beefier offerings,but we most certainly don't live in a perfect world. What to do then?It's simple--give the folks at Randy's Ring and Pinion a call and orderthe parts necessary to reinforce your 8.25.
You will recall that our Project Stealth Bomber '89 Diplomat police carwas being prep'd for the Nevada Open Road Challenge last May. We decidednot to take our chances on the stock physically abused unit out back,and instead opted to freshen it up with a new sure grip and an eventaller final drive ratio. Equipped from the factory with a 2.94 opendiff, we calculated our gear ratio based upon cruising speed versus rpm.With a 28-inch tall tire and a 2.94 gear ratio, 110 mph would require4,500 rpm while the same speed with a 2.76 gear and the aforementionedtires drops cruising rpm to a leisurely 4,000 rpm. So, we opted for the2.7s. We also took the opportunity to install an Auburn limited slipunit. The experts at Ramjet Rear End Repair were given the stage toperform the task of bringing the Stealth Bomber's rearend up to speed.
(above & right) Next, we unbolted the ring gear from the carrier. Be aware that it is aright-hand thread. Once unbolted, we knocked the gear off the case witha punch. Here, Eddie Hernandez gets the job done. |  | 
The pinion is next on the agenda. It required a 11/4-inch socket and animpact wrench. We used an aluminum punch to push the pinion out and theseal. |