KJ Jones Senior Technical Editor
August 1, 2009
Photos By: KJ Jones
Rocco Acerrio of A.R.E. Performance and Machine gives Racecraft's all-new fabricated 9-inch rearend housing a final cleaning before setting Strange Engineering's pro-geared, spooled third member in place.

Quickly bringing you up to speed on our latest full-fledged project, Boss 340 is an engine and race-car effort that we've been working on and covering here in the magazine for the last two years. This summary is more for those of you who are new to the mag. From this point forward, we hope you'll visit our website or consult past issues for the full lowdown on this exciting effort.

The engine side of the project centers on a Probe Industries-built bullet that features Ford Racing Performance Parts' 8.2-deck Boss 302 block as its foundation. The block is filled with forged rotating internals from Probe, Comp Cams' solid-roller bumpstick and valvetrain components, and is topped with Wilson Manifolds' Boss 302 single-plane EFI intake manifold (a custom piece derived from CHI's 302 intake manifold), 1,130-cfm throttle body, and Air Flow Dynamics' canted-valve, Cleveland-style aluminum cylinder heads.

Before removing our '90 Mustang LX's 8.8 rear and suspension pieces, Rocco uses a measuring tool to determine exactly how much angle the factory housing's upper-control-arm mounts create when the arms are installed. We measured 16 degrees of angle on each double-adjustable arm, and we'll use this as a baseline for positioning Racecraft's tubular arms in the fabricated 9-inch rear.

We're not aware of any other late-model Mustang magazine that has built this type of radical stroker (which, by the way, roared to the tune of 8,500 rpm on an engine dyno and put nearly 600 all-motor horses at the flywheel while doing so) for dyno testing or some other purpose. As you can imagine, our other purpose is installing the Boss engine in a Mustang. So when Editor Steve Turner asked what type of 'Stang it's going in, the answer came quickly and easily: We will use the '90 LX mentioned earlier in this report and build a drag-race Mustang, also named Boss 340.

That's the quick-and-dirty synopsis. Additional details to bring you up to date can be found in our intro story, "Here We Go Again," in the May '09 issue of 5.0 Mustang & Super Fords-and also in "Frontal Assault," our June '09 issue's play-by-play coverage of Boss 340's front-suspension upgrade, which actually is the precursor to this month's topic-the 'Stang's rear suspension.

Yes, we're ready to bring up the rear, so to speak. In this effort, we replace the project Mustang's original hind quarters-consisting of an 8.8 rear, adjustable upper control arms, stock lowers, and no brakes-with Racecraft's all-new, totally insane fabricated 9-inch rearend housing, as well as pairs of tubular upper/lower arms and an adjustable antiroll bar. Complementing Racecraft's collection are bulletproof rearend innards such as pro gears, a Pro Iron third member, 35-spline axles, and a spool, along with coilover shocks and drag-spec brakes, all from Strange Engineering.