The LS9 and LS3 block and heads are almost identical on the outside, but on the inside, they are completely different. Many people believe that the LS9 is simply a supercharged LS3, which it certainly is not. The LS9 was engineered to handle the massive amount of boost the engine will be putting out.
The LS9 supercharger is AWESOME. When you look inside of the blower, you will see just how beefy the rotors are.
We put the LS9 into the car today without the blower and it fit very well in the same location as the LS3. When we attempted to put the blower on, there was not enough room for the front drive snout and throttle body under the window; which is an issue we knew we would have what with the increased height of the engine. In the picture that we have with the engine in the car, we removed the snout so we could see what the engine would look like when sitting in the car and boy does it look cool.
Our workaround for the throttle body issue is to lower the motor about 2.5 inches to make up for the lack of space behind the firewall. This will provide a few benefits for us: it will lower the center of gravity to provide enhanced handling when cornering & it will allow us to not have to modify the car to allow the pulley's and throttle body to fit behind the firewall.
Next weekend we will be lowering the motor and working on getting the front-drive system installed. Stay tuned!
See full gallery here: ZR1 Pantera 2-9-14 Updates