Before installing the cover,...
Before installing the cover, the optional TA stud kit is installed. The studs effectively replace the main cap bolts, allowing additional clamping force. A 51/48-inch socket is used to break the four cap bolts loose, but only one bolt at a time is removed. Loctite is applied to the replacement TA stud, and a 31/416-inch Allen wrench is used to tighten the stud to approximately 10 ft-lbs. This procedure is repeated until all of the TA studs are in place. The bearing caps are reinstalled and torqued to 55 ft-lbs using the supplied TA Performance washers and nuts.
The 7.625-inch 10-bolt in your Firebird remains an enigma to the enthusiast as well as the aftermarket community. According to Jason Bailey, owner of Texas Drivetrain Performance, "Two identically equipped cars on a stock rearend can have shockingly different results. Some stock rears live long and happy lives with only routine maintenance and constant dragstrip action, while others snap axles or tear up differentials the first time a set of drag radials are bolted on. The common denominator seems to be the inconsistent quality of the metal in the factory axles and the setup of the backlash from the factory.
"Since you can't control the quality of the metal used in the stock axles, don't tempt fate. Replace them with a set of aftermarket axles. Rearends that are set at the upper end of the backlash specifications (0.008 and 0.009) or lower than 0.005 seem to experience greater parts breakage. With very tight specs, the gears can get too hot, gall, and fail. Conversely, if there is too much backlash, the pinion has added momentum when it smacks up against the ring gear. Set the backlash right in the middle of the specification at 0.006 or 0.007, and only use a qualified professional to service the rearend."
Decide what you want to do with your Pontiac, and then make an informed decision on whether the 10-bolt can survive with your driving interests and style. For drag racing applications pushing up to 425 rwhp with an automatic transmission, the 10-bolt might perform great, whereas an identically equipped six-speed might not fare as well. If you intend to drag race on a regular basis, seriously consider a 12-bolt. For Birds looking to run 8s and 9s, a Ford 9-inch or even a Dana 60 will serve you well.
Road racers shouldn't even consider a 12-bolt or Ford 9-inch unless competing in a "tube chassis" type race series. Instead, road racers should invest in a Torsen T2R differential and build a maximum-effort 10-bolt. Since a 12-bolt and Ford 9-inch are both heavier and require more power to turn, slight gas mileage and rear-wheel power losses should be expected. For the street cars and occasional drag and/or road racers, a properly prepared 10-bolt will likely serve you well. Invest $500 to weld the axle tubes, install aftermarket axles, put on a TA differential cover, and avoid a costly repair bill.
The housing-cover mounting...
The housing-cover mounting surface and TA differential cover are wiped down with grease and wax remover. The two cover bearing-cap load bolts are backed out using a 71/48-inch wrench, and RTV is applied to the face of the differential cover and the cover gasket. Next, the rearend cover gasket is placed on the cover and lined up with the bolt holes, while the RTV is allowed to cure for a few minutes.
Each of the 10 TA differential-cover...
Each of the 10 TA differential-cover bolts is inserted in the housing. The factory brake shield on the top of the housing can't be reused due to the thickness of the TA cover, but the brake line brackets on the top, right, and left side of the housing fit fine with the longer cover bolts that are supplied. Once all the bolts are started, a 11/44-inch Allen wrench on a socket is used to snug each of the cover bolts; then they are torqued to 22 ft-lbs.
The main benefits of the cover...
The main benefits of the cover are the load bolts located at 3 and 9 o'clock. RTV is applied to the threads on the load bolts to prevent oil leaks, and a 11/44-inch Allen wrench is used to pre-load the bolts to 10 ft-lbs. The jamb-nuts that keep the load bolts from backing out are tightened with a 71/48-inch wrench.
Eaton calls for conventional...
Eaton calls for conventional differential fluid due to the composition of the carbon disc packs, so after removing the fill plug on the side of the differential with a 31/48-inch socket head, just under 2 quarts of GM 80W90 gear oil is inserted nearly to the fill line. Then the fill plug is inserted and tightened to 26 ft-lbs. The disc brake calipers and rotors are reinstalled, and the wheels are remounted. Proper break-in procedures for the rear gears are followed before driving the car aggressively.