Automotive Specialists Build A Gorgeous Stroker Chevrolet 409


Automotive Specialists Build A Gorgeous Stroker Chevrolet 409


Everything old someday will become new again. Chevy first debuted the W Series engine back in 1958. That was the 348, and the famous 409 followed soon after. But by 1965 they were gone when the excellent Mark IV big blocks began appearing in cars and trucks.

But even though the 409 had a short lifespan, it still is a beloved engine. And Keith and Jeff Dorton of Automotive Specialists gave the famous engine a big update with all-aluminum block and heads, port fuel injection, a custom modern intake and several other really cool touches. Much of this wouldn’t even be possible without a few critical Holley and MSD components.

Check out the video and see for yourself!

Hunnycutt 409 overview

Those scalloped valve covers make the W-series 409 instantly recognizable. On the dyno, our updated mill made an impressive 526 horsepower and 557 foot-pounds of torque.

Hunnycutt 409 cylinder head

The defining feature of the 409 is the unique cylinder head that’s practically flat with no combustion chamber. Instead, air and fuel is combusted in a wedge-shaped pocket that’s created in the cylinder bore when the piston is at top-dead-center.

Hunnycutt 409 Port Fuel Injection

The 409 was obviously never designed with the intention of supporting port fuel injection. But Automotive Specialists was able to add it and easily control all the parameters for proper engine control by using one of Holley’s Terminator X EFI ECU’s.

Hunnycutt 409 fuel map adjustment

Jeff Dorton makes quick adjustments to the fuel map while the engine is on the dyno.

Hunnycutt 409 MSD 6EFI box and coil

Most modern engines utilize one coil for every spark plug. But that wouldn’t look quite right with the classic 409. We stuck with a single coil controlled by an ignition control box. This was handled by MSD’s 6EFI ignition box and 6EFI coil. These are like the old gold-standard 6AL box and coil, but thankfully updated to work efficiently with fuel injection systems

Hunnycutt 409 digital dash monitoring

Automotive Specialists works primarily with Holley ECU systems, so it only made sense to add one of their digital dashes to the dyno control board. Hooking up the dash to work with each new engine is only a matter of a couple of plugs, and the dash is configurable so they can monitor whatever parameters they like for each specific engine.


9 Posts