The freshly rebuilt Six Pack motor was running well and had good power, but not the kind of power that I looked for. I took the car to a chassis dyno, and it pulled 341 hp at the rear wheels, which is roughly 410 hp at the flywheel. The cam I was running had 230-degrees duration at .050-inch lift, together with 9.5 to 1 compression pistons, it made for a mushy bottom end as far as torque and throttle response goes. The cam and the ported 906 heads I was running wouldn't really start pulling hard until you got close to 3,000 rpm, and would pull like mad from there on up to 6,000 rpm. Another annoyance was the finicky cold-weather starting/warm-up behavior that comes with a performance cam and Six Pack carbs using the old-style choke setup. I had solved the high-rpm highway cruising problem by installing the five-speed, but now I needed to address all of these street-drivability issues that come with the typical high-performance carbureted engines built using '60s technology. I wanted a car that wears '60s musclecar sheetmetal, but has '90s drivetrain technology underneath. I wanted a car that idles at 700 rpm, has crisp instantaneous throttle response, can get better than 15 mpg, can start instantly with one turn of the key in any temperature, and produce well over 700 hp and 800 lb-ft of torque at less than 5,500 rpm.
How was I going to get the top-end power that I wanted? Nitrous was out because I want the power-on-demand all the time and not just at full throttle; plus I don't like the idea of always refilling the bottle. Turbocharging was out because I didn't like the idea of all that extra exhaust tubing that would have to be fabricated to drive the turbo. Nope, the answer was supercharging. To use a centrifugal supercharger, you have to blow air into the intake manifold, which would mean blowing it through the carbs. Well, I didn't want to mess with all the tubing fabrication it would take to plumb air into all three carbs of the Six Pack, so those were going to have to go. The answer, of course, was to use fuel injection. With a modern electronic fuel-injection system I would solve both the blow-through problem and the driveability problems.
The first part of the puzzle was the EFI system. I decided to go with a fully programmable system manufactured by Accel. Rance Baxter set me up with a complete Accel/DFI system, which included the ECU (engine control unit or computer), the software to program it (called CalMap), throttle body, fuel rails and injectors, specially-modified Edelbrock Performer RPM manifold, high-volume electric fuel pump, fuel pressure regulator, MAP (Manifold Absolute Pressure) sensor, wide-band oxygen sensor, manifold surface temperature sensor, throttle position sensor, coolant temperature sensor, braided steel fuel lines, AN fittings, knock sensor, and, of course, the giant octopus-like wiring harness to tie it all together.
There are several well established manufacturers of centrifugal blowers: Vortech, Paxton, ATI Procharger, and Powerdyne, just to name a few. They make all kinds of complete bolt-on kits, but none of them made a kit for a big-block Chrysler. I found the answer with SD-Concepts Engineering located in Warwick, Rhode Island. They have been custom fitting centrifugal superchargers to Mopars for many years and had a complete bolt-on kit for my big-block Chrysler engine. He set me up with a complete kit that included an ATI Procharger P1SC supercharger, and custom mounting brackets for both the supercharger head unit and the alternator.