So you want more power, but you like the streetability of a compression ratio that allows you to pull into any gas station, and a camshaft with a duration that lets you engine purr like a kitten. Well, Paxton's blow through supercharger kit for 383 and 440 Wedge engines, PN 1201860-1 satin or PN 1201860-1P polish finish, is probably just what you need. The Paxton kit is based around the oil fed, spur-gear-driven Novi 1500 centrifugal supercharger. Under normal driving conditions, this supercharger is designed to operate at 7-9 p.s.i when equipped with a standard 3.875-inch diameter 10 pound drive pulley. Depending on the actual condition of the engine and boost level being used, horsepower gains can be quite notable.
The Novi 1500 supercharger comes standard with the aforementioned 10-rib diameter pulley, although other pulley sizes are optionally available. Also included in the kit are Paxton's twin-billet-aluminum supercharger mounting plates, which feature an integrated manual drive-belt tensioner and alternator mounting provisions. The actual supercharger drive-assembly features a black anodized, six-inch diameter billet-aluminum crank pulley and a 10-rib supercharger drive belt with spacer. This bolts up to the OE two-groove crankshaft pulley and balancer using the provided mounting hardware. Ducting consists of a four-inch inlet duct complete with silicone hoses, stainless-steel band clamps, and a conical air filter. There is also a 3.5-inch aluminum discharge tube, and an aluminum race-type bypass valve with tube and mounting flange. Finally there's a cast-aluminum carburetor "hat" used instead of the conventional air box like the one used on Paxton's 120851/120852 small-block Mopar supercharger applications; a necessary compromise due to space limitations under the hood.
Here's what our 440 Mopar big-block looks like before we began our installation. Other than a set of Mopar Performance finned-aluminum valve covers, and an Edelbrock intake, it's basically stock.
With forced induction, a "boost-referenced" carburetor is an absolute must. For this particular application, a number of carburetors were tried but ultimately, Paxton technicians settled on a Quick Fuel Technology Q-750-BAN/750-cfm blow-through carburetor equipped with annular boosters.
First step? Out comes the radiator. Since the OE fan will NOT be re-used, Paxton Automotive Corporation recommends the use of a twin fan aftermarket cooling module rather than the stock radiator.
Fuel pressure must also remain constant, so a high performance electric fuel pump and fuel pressure regulator is also required. Paxton also recommends the use of an aftermarket ignition amplifier to not only maintain optimum spark, but also protect the engine from over revving. And lastly, although not shown in these prototyping photos, an aftermarket puller fan or fans is recommended, since the OE fan blade will have to be removed.
"The hardest part about any retro-fit kit is the fact that factories weren't all that consistent when it came to their accessory-drive engine brackets, etc." says Paxton engineer Bob Andress. "Through our R&D program, we have found that there are a number of different style pulleys, alternators, and water pumps used on these early Mopars, which makes building a universal-fit kit like this one quite a challenge. Andress continued. "You also have the issue of all the aftermarket mounting brackets and engine pulleys that are available on the market. Taking into consideration the that most of our Mopar Big-Block customers are street machine enthusiasts-as we doubt that many concours restorers will want to install one of these kits-we've tried to make it as "user friendly" as possible, but those owners with modified Mopar big-blocks MIGHT have to use a little bit of imagination!"*
It's highly doubtful that your car is already running a blow-through prepped carburetor, so you will have to replace it.
So, our test vehicle was filled with 91-Octane fuel, and strapped to the dyno. Our baseline test produced the following rear-wheel power numbers; 285 horsepower at 5,300 r.p.m., and 314 lb/ft of torque at 3,000 r.p.m. These numbers are very typical of a basic rebuild of a 440, and just about what we expected. After we added the Paxton kit and fed the big block 5-1/2 pounds of pressure, the power jumped to 417 horsepower at 5,300 r.p.m., and 417 lb/ft of torque at 4,400 r.p.m. No bad for a universal bolt on.
*Note: These photos show the prototyped 440 system. Installation procedures may differ with the production system. Be sure to follow the Paxton installation manual you get with your kit.
