Tom Derych’s Blown Hemi Charger Is The Mopar Muscle Car He Always Wanted

Tom Derych spent his teenage years launching a 440-powered Dart Sport down New York National Speedway, and fifteen years looking for a real muscle car to replace it. He found a Sublime Green 1970 Charger at a show in 1989 with a blown 440 that looked spectacular and barely ran. What he built from it displaces 472 cubic inches and wears 1966 iron Hemi heads. Read on for how the combination came together.

A guy who spent his teenage years launching a 440-powered Dart Sport down New York National Speedway does not wander into a car show and buy the first Charger he sees. Tom Derych had been looking for fifteen years by the summer of 1989, long enough to have watched the good cars get scarce and the prices climb past what a working person could justify. He was specific about what he wanted, too: something from 1969 or 1970, because the Dart had been fast and fun but had never felt to him like an actual muscle car. So when a Sublime Green 1970 Charger caught his eye at a show that summer, something about it had to be worth ending a decade and a half of searching. It was not the paint.

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A Blower That Looked Better Than It Ran

What stopped him was what a previous owner had already done to the engine bay. The car’s original 383 was long gone, replaced by a 440 wearing a 6-71 style supercharger, the kind of installation that photographs beautifully and draws a crowd at every show it attends. Derych knew enough about Mopar big blocks to recognize both the appeal and the problem. The engine looked considerably better than it ran. Anyone who has spent time around blown street engines knows that particular disappointment, where the hardware is all present and the combination behind it was never actually thought through.

Building 472 Cubic Inches Out of a 440

Rather than chase the existing build with band-aid fixes, he tore it down and started over from the crankshaft up. Chrysler’s factory 440, an RB series wedge, uses a 4.32 inch bore and a 3.75 inch stroke to arrive at its 440 cubic inches, which is already a substantial engine by any measure. Derych went past it, fitting a Kellogg stroker crankshaft to bring total displacement to 472 cubic inches, comfortably larger than either the stock 440 or a factory 426 Hemi. JE forged pistons fitted with plasma-moly rings went in specifically to survive boost, because a supercharged engine punishes cast components in ways a naturally aspirated one never will.

1966 Hemi Heads on a Wedge Block

The cylinder heads are where the build stops being a hot rodded 440 and becomes something more unusual. Derych bolted on a set of 1966 iron Hemi heads, freshened and running the Hemi’s own factory valve sizes, 2.25 inches on the intake and 1.94 on the exhaust, dimensions that dwarf anything a wedge head ever carried. Hemi heads on an RB wedge block is a combination with real history behind it and real complexity in front of it, since the valve angles, pushrod geometry, and rocker arrangement all differ from what the wedge block was designed around. He kept the valvetrain close to period correct with stock Chrysler rocker arms, then improved its odds of survival with COMP Cams valve springs, solid lifters, and titanium retainers.

What a 6-71 Actually Demands

That blend, vintage architecture with modern internals, is the smartest thing about the whole project. A 6-71 supercharger does not care how much sentimental value a part carries. It puts cylinder pressure into an engine continuously rather than only when the driver asks for it, and everything from the head gaskets to the rod bolts to the fuel delivery has to be specified around that reality. Compression has to come down to keep detonation away. Ignition timing has to be managed carefully. The blower drive itself is a wear item that needs attention on a schedule most street car owners are not used to keeping. None of that is visible when the hood is up, which is exactly why so many blown show cars run poorly.

Why the 1970 Charger Is the Right Canvas

The car underneath deserves the effort. The 1970 Charger is the last year of the second-generation body, the one with the full-width loop bumper grille and the wraparound taillights, and it is widely regarded as the best-resolved version of a design that was already among the most striking things Chrysler produced. Sublime Green is a High Impact color that has aged from a period curiosity into one of the most sought-after finishes on any Mopar. It is a car that makes an impression standing still, which raises rather than lowers the standard for whatever is installed under the hood.

The Case for Building It Yourself

There is also something worth noting about how this car came together. It was not commissioned from a shop and it was not bought finished. Derych built it himself, drawing on decades of hands-on experience with exactly this family of engines, which is the reason the parts list reads as a coherent plan rather than a collection of catalog highlights. Owner-built cars tend to show their thinking in the details, and this one shows a builder who understood the difference between what looks fast in a parking lot and what survives being driven the way he had been driving Mopars since the 1970s.

The Most Expensive Part Was Patience

For anyone weighing a similar project, the lesson sits right at the front of the story. The most expensive part of the Charger was not the supercharger, the crankshaft, or the Hemi heads. It was the fifteen years of patience spent waiting for the right starting point, followed by the willingness to pull apart an engine that already looked finished. Plenty of people would have driven that car home in 1989 and left the blown 440 alone. The version that exists today is the result of not doing that.

Sublime Green and the High Impact Palette

The color deserves its own mention because it is doing real work here. Sublime Green belonged to Chrysler’s High Impact paint program, the range of deliberately loud finishes introduced at the end of the 1960s to court younger buyers, alongside names like Plum Crazy, Go Mango, and Panther Pink. At the time they were polarizing and frequently ordered by the people least concerned with resale value. Fifty years later those same colors command significant premiums, because they photograph well, stand out in a field of conservatively restored cars, and date a car instantly to the exact moment Detroit stopped taking itself seriously. A Sublime Green Charger reads as period-correct in a way a tastefully painted one never quite manages.

Why the Second-Generation Charger Body Still Wins

The 1968 through 1970 Charger is regularly cited among the best-looking American cars of any era, and the reasons are structural rather than purely nostalgic. The flying-buttress roofline, the full-width grille, and the coke-bottle body sides give the car a sense of mass and motion that holds up from any angle, and the 1970 revisions tightened it further with the loop front bumper. It is also a physically large car, which means the engine bay will accept a blown big block without forcing the compromises a smaller platform would demand. Form and function line up unusually well here. A supercharger poking through the hood of a 1970 Charger looks intentional in a way it simply does not on most other cars.

Where the 6-71 Supercharger Actually Came From

The blower bolted to this engine has a stranger origin than most owners realize. The 6-71 designation refers to a Detroit Diesel two-stroke engine, a Roots-type supercharger originally engineered to force air into diesel truck and industrial engines, not gasoline street cars at all. Drag racers discovered in the 1950s that the same positive-displacement blower, scaled and adapted with a gear-drive setup, could be belted onto a gasoline V8 to force enormous amounts of air into the cylinders on demand, and by the 1960s the 6-71 had become the default look and sound of serious drag strip horsepower, showing up on everything from Top Fuel dragsters to blown Funny Cars. Its migration onto street cars like this Charger followed the same logic that drove Derych’s own build: real drag strip hardware, scaled back just enough to survive daily driving, on a chassis built to carry it. The unmistakable whine a Roots blower produces under load, along with the visible pulley and belt drive standing above the hood line, are as much a part of the car’s identity today as the paint or the badge on the fender.

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