The only thing standing between you and the flywheel now are six bolts; turn 'em quick and the motor won't spin over. We should have mentioned long ago that the negative battery cable should have been disconnected to prevent accidental spinning of the engine at any time during this installation. The clutch disc and pressure plate are fairly heavy, so be ready to grab them as that last bolt comes out. |  | 
The six flywheel-to-crankshaft bolts are best removed using an air-powered wrench, NASCAR style. After they're all loose, some fairly hard hits with a rubber mallet about the perimeter of the flywheel will be needed to unseat it from the crankshaft. Note that even if you aren't replacing the flywheel with a new one, you'll still need to remove the stock one, as it needs to be taken to a shop to be resurfaced and rebalanced to match the new clutch assembly. |
After the stock flywheel came off, we put the new billet SPEC unit in place and it was time to replace the pilot bearing. The very front of the transmission input shaft rests inside this bearing, ensuring everything between the crankshaft and the transmission remain properly lined up. SPEC demands that this bearing be replaced, and one is included. Though other methods exist to get the sucker out of the back of the crank, the best way is via a pilot bearing puller, as seen here. | 
No special tool is needed to install the new pilot bearing; just a socket of the appropriate diameter and a hammer. Gentle taps are all that are needed to get the bearing started and going in straight. The bearing should only be installed until it is flush with the back of the crankshaft; pushing it too far can purportedly cause a pressed-in oil galley plug to be disturbed. | 
The flywheel-to-crankshaft bolts are ready to go back in, and it's critical to use some red threadlocker on them, regardless of what the GM repair manual says. We reused the stockers, but it's probably best to pick up some new ones. Final torque specifications for these bolts are 74lb-ft on LS1s, but this reading needs to be preceded by two passes of 15 lb-ft and 37 lb-ft, respectively. Be sure to tighten them in a criss-cross fashion (i.e. tighten one bolt and then skip over the next one as you move in a circle). |
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Lying side by side, it's clear the stock clutch disc (right) differs greatly in design and construction from the Stage 3 SPEC unit (left). The new unit is a "6-puck" design with carbon semi-metallic friction material and high-torque sprung hub. If the Stage 3 Plus is ordered, the disc will actually look more like the stocker as it will be a full-faced type disc. | 
In order to hold the clutch disc in place while the clutch pressure plate is installed over it, the SPEC-provided clutch alignment tool is simply popped in place. Its tip sits in the pilot bearing, ensuring that the clutch disc stays put while the pressure plate is torqued in place. Make sure the sticker on the clutch disc that says "FW Side" (i.e. "flywheel side") isn't visible at this point! |