1996 Chevy Caprice 9C1 Engine Modifications - Killer Whale

Brand-new clutches and steels are used throughout. Level 10 uses high-performance pieces and contributes the total torque capacity of a 4L60E/4L65E to the quality of the clutches and how well the valvebody and front pump are modified. Because our reverse-input drum was badly worn, we had to replace it with a new one. No worries for us, as Level 10 is used to this kind of carnage and promptly pulled one off its shelves and put it on our tab.

Brand-new clutches and steels are used throughout. Level 10 uses high-performance pieces a

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At this point, many dragstrip enthusiasts start throwing all sorts of horsepower-enhancing parts on their ride. This may sound like fun, and it often is, but it's not the most effective way to drop e.t.'s. Instead, it's usually better to concentrate on getting the power that you already have and putting it to the ground by improving ef-ficiencies in the driveline and suspension. With that in mind, our next round of mods would include a higher-stall torque converter and some mild suspension upgrades.

Because our goal was to have a streetable, strip-capable machine, we wanted a torque converter that would put the engine revs into the meat of the LT1's torque peak without the excessive slippage that would hurt performance or fuel economy. So we kept our goals realistic and headed over to Level 10 Performance in Hamburg, New Jersey, for a new converter. Once we gave proprietor Pat Barrett the detailed intention of our ride, he recommended one of his 10-inch performance converters, and on top of that an internal transmission upgrade because of the dragstrip action our car was going to see.

In addition, the switch to the heavier-duty internals from a later-model 4L65E would ensure greater torque capacity and dependability. With the higher stall converter and the firm shifts provided by the specially modified valvebody, the car felt incredibly crisp-as if it lost 1,000 pounds.

Next up, we looked to the suspension for more e.t. We thought it would be a good time to upgrade our leaky shock absorbers for better wheel control and the rear control arms for better traction. Since the rear control arms are pivotal in controlling that stonkin' huge 8.5-inch rear axle, we opted for solid billet aluminum units from Metco Motorsports. They replace the flimsy factory stamped steel units and eliminate all the rubber bushings at each contact point for better control. In their place, stiffer yet pliable polyurethane bushings do a much better job of positively locating the rear axle. Even better, Metco offers these control arms in factory or extended length versions; the latter relocates the axle housing rearward about an inch to properly position the rear wheel within the wheelwell housing, which is a problem that has plagued all Caprices with full-radius rear wheelwells from 1994-96. We opted for the extended-length units.

On 4L60E and 4L65E transmissions, the weak link is the front pump and its variable output design that relies heavily on the line pressure regulator. On the bottom, we see that Level 10 uses an O-ringed plug that receives a higher-rate spring along with a coated pressure regulator valve to bump up internal line pressure to high-performance specifications. Barrett mentions that this alone will greatly improve transmission performance and service life.

On 4L60E and 4L65E transmissions, the weak link is the front pump and its variable output

To match the improved performance the new control arms would provide, we then installed a set of Edelbrock's IAS shock absorbers on each corner of our Killer Whale. These shocks replace the factory units perfectly and offer much improved control over slow- and high-speed maneuvers thanks to an internally variable valve that varies firmness based on shaft velocity.

Because the Killer Whale was a former highway patrol vehicle, it was geared with rather tall 3.08s. We knew that for better e.t.'s we had to step up the gearing a bit for greater torque multiplication to get this two-ton titan out of the hole. While we were tempted to go with 4.10s, we decided to install 3.73s to maintain good fuel economy on the highway. When you go shopping for a gearset, make sure it's for a '91-96 B-body, as it must have the proper pinion shaft size to accept an ABS toner ring. Speaking of which, that's another expense, so plan to spend another $30 for the sensor ring because it's not included with the gearset that you'll buy.

A quick search on eBay revealed a plethora of used gearsets from various sellers. We found a set of used OEM 3.73s, purchased a new ABS toner ring from our local Chevy dealer, and brought everything over to our local GM performance experts at J&T Auto in Huntington Station, New York.