Well, the first thing was that I had to make up for the fact that although the RoadMaster's LT1 had HorsePower to spare, it did not have the TORQUE of a 455, and I wanted those low 14's. I opened it up as much as I could on both ends, feeding the intake through a Dual Snorkel Corvette intake plenum, though a larger, F-body MAF and a polished manifold. I may eventually go for a port there, but for the moment, breathing is great. On the exhaust side, I got some ceramic coated tri-y headers from Clear Image Automotive, high-flow cats and went though some of the last of Doug Thorley's B-Wagon CatBacks (lucked into finding them being liquidated by the factory on eBay!). It sounded like a dragster with his system, so I swapped the mufflers for DynoMax Super Turbos and put in an H-pipe. They still sound great, but don't wake up all of the neighbors and set the dogs barking for blocks around like the Thorley's did . I also put on LT4 composite covers to give me clearance for 1.6 roller rockers and beehives, allowing the engine to pull to a decent shiftpoint (also added the LT4 knock module to the PCM so that it doesn't mistake the valvetrain noise for knocking). The ignition electronics, cap, rotor and coil are all now MSD and I'm running Taylor 8.5mm wires with Platinum Champion plugs.