Rocco Acerrio of A.R.E. Performance...
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...
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.
 We also took measurements...  We also took measurements of Boss 340's actual weight just prior to starting the rearend upgrade. We'll use Proform Parts' really cool, affordable vehicle scale to monitor various weight specifics throughout the remainder of our project. Check out the sidebar, Weights and Measures, elsewhere in this report for more details about the system. |  This is what a killer fabricated...  This is what a killer fabricated 9-inch Mustang rearend and all of its supporting pieces look like. Shown are Racecraft's all-new housing, adjustable upper and lower control arms, an antiroll bar, and all of the associated fastening hardware. The setup is complemented by Strange Engineering's Pro Race axles, Pro Iron third member, double-adjustable, coilover rear shocks, and Pro Race rear brakes, making this a can't-miss, bulletproof package for the backside of a Mustang, which is capable of harnessing far beyond 1,000 rwhp. |  Working with a twin-post hoist...  Working with a twin-post hoist and transmission jack make tasks such as dropping Boss 340's 8.8 rearend assembly quick-and-easy for Rocco and Tony. |
 Robert V. of Fast Track Performance...  Robert V. of Fast Track Performance installed our project 'Stang's mini-tubs several years ago. With the tubs and Racecraft's narrowed 9-inch rearend, we'll be able to comfortably stuff 12 inches of tire tread (width) and 30 inches of diameter under Boss 340 if we want to go that big. |  We like to think of this as...  We like to think of this as the pice-de-resistance for this segment of our build. Racecraft builds its super-fortified rearend housing around a series of wickedly bent, 1/8-inch-thick steel plates as opposed to welding individual squares together to make the differential housing. |  Welding axle tubes to the...  Welding axle tubes to the housing's center section is taken to the next level with the fabricated 9-inch. Check out the way Racecraft attaches the tube by laying it inside a channel that's incorporated in the center section, and then power-welding the entire works to ensure that it will not rotate-ever-when horsepower and torque are applied. |
 This Strange Engineering Pro...  This Strange Engineering Pro Iron center section is the heart and soul of our 'Stang's new rear. The nodular 9-inch differential is about 8 percent stronger than Ford's factory 9-inch case. Our project's pumpkin has been loaded with chrome-moly bearing caps, a steel Pro Race spool, and a set of 4.57-ratio pro gears that should get the Boss Pony out of the gate quickly. |  A generous bead of Right Stuff...  A generous bead of Right Stuff black silicone is applied to the housing before the Strange differential is seated on ARP studs. Rocco makes sure alignment is true so that he only has to wrestle with the 33-pound pumpkin one time. |  This 12-point, 5/16-inch wrench...  This 12-point, 5/16-inch wrench is one of the few items that require minor modification. Clearance between the differential's case and two of the ARP studs is close and doesn't allow placing a wrench over the fastener. Grinding a slight edge off of an old, cheap wrench does the trick. |