KJ Jones Senior Technical Editor
May 1, 2009
Photos By: KJ Jones
Our 600 (naturally aspirated/flywheel) horsepower Boss 340 small-block lays in wait for its chance to scream again as the high-revving motivator of the '90 LX project 'Stang that will bear the same name. A.R.E. Performance and Machine of Simi Valley, California, is taking the lead on building this Pony, which is truly getting a new lease on life after sitting unfinished for 5 years.

Horse Sense: When it comes to the Mustang hobby and upgrading or building complete 'Stangs, never rule out using the good-old American barter system as a method of scoring parts, services, or even complete Mustangs if a deal can be agreed on. We acquired the fully 'caged '90 hatchback LX race-car chassis that will be "Boss 340" and a complete second LX roller that was being sold as a parts car (clean interior/exterior pieces, windows, and so on) in a blockbuster swap deal. (Your tech editor gave up a stock 5.0 A9L PCM and wiring harness, $400 cash, and $100 to our buddy, Johnny Grum, for stripping what we wanted from the parts car, taking what was left to the junkyard, and then hauling the racecar and parts to us from Phoenix, Arizona.) With economic times being a lot tougher now than they were back in 2003, you should always at least try and go the trade route when making online or in-person deals with fellow enthusiasts.

The wide variety of changes and upgrades that can be made to late-model Mustangs has long been one of the main reasons so many of us are totally consumed by the hobby.

Seriously, guys, let's face facts. While the virgin/bone-stock concept does have its place in the grand scheme of 'Stangbanging, driving an untouched Pony doesn't come anywhere near the thrill (and satisfaction) an enthusiast experiences when his hopped-up ride goes above and beyond expectations after mild or wild changes are made. Right?

The other reason is, honestly, we really don't have any ambitions of running in the 7s, or even reaching the 8s with our project Mustang, although the chassis we're starting with is mini-tubbed and fully caged. Our goal is to simply build a good, lightweight, true 10.5-inch (slicks) race 'Stang and use it to see just how well its Probe Industries-built, fuel-injected Boss engine will perform on the dragstrip-with a four-speed transmission.

This is our project Pony as it looked on the day it was delivered in July of 2003. While calling the 'Stang "raw" definitely is an understatement, we jumped at the chance to get this chassis when its owner suggested a trade deal that was too good to pass up (see Horse Sense).

Editor Turner put it best when he said, "Mustangs are made to be modified." We support our leader's sentiment each month through the research we do with the many bolt-on parts the aftermarket offers, and also through our steadily growing armada of project Mustangs.

Those of you who have followed the engine-build and dyno-test phases of our Boss 340 project, should also be somewhat familiar with the '90 LX Mustang we're introducing in this report. From the outset of our mission to build the mega-cool high-revving, Cleveland-headed, EFI bullet you've been reading about, we also let you know that the buck doesn't stop with simply making big steam on the dyno. Our ultimate plan is to use the innovative modern-day Boss engine in a full-on, drag-purposed Mustang, a car which your tech editor, along with Rocco and Tony Acerrio from A.R.E. Performance and Machine of Simi Valley, California, will craft over the next few months from the '90 hatchback shown on these pages.

The four-gear tranny is just one of the cool tricks we're trying with our setup, as are the Air Flow Dynamics SP4VS canted-valve, aluminum cylinder heads that sit atop the 8.2-deck short-block. When it's all said and done, Boss 340 will be a perfect candidate for the Pacific Street Car Association's Mustang Maddness class, an Open-Comp-style eliminator sponsored by Ford Racing that is open to Ford-powered Ponies of all years, engine/drivetrain configurations, and so on. Should our 'Stang have enough steam to consistently run 10.60s, or even 9.60s, we also will consider trying Mean Street or Quick Street, PSCA's index category for cars that run in those e.t. ranges.

The extensive (for a '90) rollcage and through-the-floor subframe connectors were features that confirmed we really scored by acquiring the 'Stang for the collective and paltry sum of $700 (Mustang parts and cash). Two different chassis fabricators estimated the work that was already done easily could have cost nearly $3,000 to complete.

Over the years-30 years and counting as of April 2009-Fox-body Mustangs have come to be considered as the "best" Ponies to modify for the dragstrip. With the new and relatively unknown '10 'Stangs poised for arrival in dealerships, S197s still going plenty strong, and New Edge ('99-'04) cars starting to gain popularity among newcomers to the Mustang game, it's amazing that the simplest and oldest of the late-model 'Stang platforms is still so highly revered. The Fox-body continues to live up to those accolades, breaking e.t. and speed records, and winning championships in sanctioned drag-race competition. (NMRA Super Street Outlaw racer John Urist parked his '00 Saleen-a Mustang that he says took years to achieve success-immediately after the '07 season and replaced it with the '93 Fox coupe that carried him to the SSO title in 2008.)

Boss 340 (the car) will never be a Super Street Outlaw champion, let alone a contender. Nor will it hang with any of the Ponies that dominate Drag Radial, Hot Street, Renegade, or any other fiercely competitive heads-up categories in the NMRA. One major reason for this is because the project is being done in California, thousands of miles away from NMRA action.

Once the mini-tubs were in, the car was taken from Robert's shop and propped up on jackstands in the garage for additional fabrication and finishing work, including sealing the firewall, making replacement front inner-fender panels, repairing the core support, and painting the rollcage.

Naturally, Project Boss 340 will also be equipped with the latest, hard-core racing hardware for '79-'93 drag 'Stangs, which we'll certainly discuss in great detail in our future reports on the build. For now, keep reading as we take you through an introductory chronology of photos and captions that show you what we're workin' with. Basically, we're going at this project with a really good "lump-of-clay" race chassis (with has a pretty interesting story of its own), and an earnest ambition to make the 'Stang worthy of carrying the legendary Boss name.

Stay tuned, 'Stang fans, this one is gonna be good!

NHRA rules require a racecar to have a completely sealed firewall to prevent flames from entering the cockpit in the event of a fire. All of the holes in our project car's firewall were fully welded shut. Welding and grinding on a firewall is labor intensive, but it's hands-down the best way to close up this area of a racecar.

Check List
Being organized and laying out a good gameplan is a critical strategy that helps ensure the success of a full-on race-car build. While some projects may require elaborate spreadsheets and graphs to keep things running smoothly, we made a simple bullet-point rundown of parts or tasks needed for Boss 340's completion. Here's a peek at some of the items on our extensive agenda:

*K-member and front suspension
*Front brakes
*Rack and pinion
*Headlights, taillights, turn signals, and bezels
*Motor plate/mid-plate
*Master cylinder
*Clutch linkage
*Cooling-system plumbing
*Harwood Lexan windshield
*Window net
*Five-point harness
*Parachute and mount
*Fire-suppression system
*Littelfuse wiring system
*Switch panel
*Sunroof hardware
*Complete weatherstrip kit
*Rear suspension
*Kill switch
*Rear-hatch hardware
*Rear wing
*Fuel system
*Nitrous fuel system
*9-inch rearend (51 7/16-inch backside of flange to backside of flange)
*Wheels and tires

We shot the rollcage, accessories frame, and mini-tubs with gloss black paint and clearcoat. A complete 8.8 rear was also added at this time.

Obtaining an NHRA chassis certification was a major moment in our 'Stang's pre-magazine-project history. Tech Inspector Eric Lowe affixes a Sportsman cert sticker to the main hoop of the rollcage.

A detailed look at the certification shows that at the time (early 2005), the chassis was deemed safe enough by NHRA for e.t.'s of 7.50 or slower. This was one of the last 7.50 certs that was issued in Southern California, as the SFI's new 25.5 chassis specs for 7.50, 3,600-pound door cars went 100 percent into effect not long after the inspection was done on our 'Stang. Unfortunately, KJ's PSCA Wild Street effort was forced to come to a screeching halt just after the car was certified only to be briefly revitalized in 2006 when Dave Rifkin and Ryan "Junior" Schotzel of DS Racing in Simi Valley, California, were commissioned to mock-fit a drivetrain in the 'Stang, which included modifying the floorpan, and installing a wide-ratio (2.78 first gear), Top Loader four-speed tranny, McLeod RXT twin-disc clutch, and Long vertigate shifter underneath the LX. Dave and Junior also installed Wolfe Racecraft's super-trick, Pro Stock-style clutch pedal.

DS Racing created this bitchin', fully removable, sheetmetal trans tunnel to replace the material that was taken out of the floor In the spirit of such notable three-pedal Mustang racers as Larry Geddes, Bob Pott, Mike Sodano, Don Bowles, and Ward Alston, using a stick transmission has always been the plan for this Pony. As the project progresses, we hope to some day replace the pro-shifted Top Loader with a full-on, clutchless gearbox from G-Force.

Remember the frame structure that was created for a fuel cell, batteries, and more? It is now completely finished with sheetmetal panels and looks good with everything is in place.

Whenever a battery is mounted in the rear of a drag car and isn't protected by a separate box, the NHRA requires a rear bulkhead panel. Former NMRA Real Street racer Andy Burnett fabricated this sick rear panel for our car several years ago. We'll finally put it to use when Boss 340 is completed.

Inside the LX, the aluminum racing seats are secured with Holcomb Motorsports' brackets, and the factory dash and center console pieces are held in place with Duzs fasteners for quick-and-easy removal whenever necessary. The dual nitrous-bottle bracket is a $10 swap-meet score, which Dave and Junior modified to be fully removed from the passenger side for whenever someone is occupying the second seat.

Five years after KJ acquired the '90, we're finally at a point where a new and hopefully final life is beginning for a Mustang that has definitely been through a lot!

This is how we found our project LX in November of 2008. After being parked in your tech editor's garage upon its return from DS Racing in 2006, the Mustang sat untouched and literally became a storage shelf for miscellaneous parts and other items.

Before taking the 'Stang out of its tomb, a compressor and plenty of air was used to remove layers of dust that had amassed inside the car over the years.

Rocco (left) and Tony Acerrio of A.R.E. Performance and Machine have accepted the challenge of transforming our rolling chassis into the dragstrip terror we're envisioning it will be when Boss 340 is completed. As builder of our project T-top coupe's 350ci, 830-rwhp small-block, A.R.E. has shown us what it can do with engines. This build definitely is a much-bigger assignment, but the duo is ready and, barring disaster, feels our Boss Mustang could possibly hit the strip before the end of the '09 racing season.

Strange Engineering's 9-inch rearend housing will be installed under our Boss, along with rear-suspension components from Racecraft. Since the back of the Fox is mini-tubbed, Rocco measures the length of the 8.8 rear and calculates the length for the new rear. For those who are curious and plan on going this same route with a '79-'93 Mustang chassis at some point, a rearend measuring 517/16-inch (from the backsides of both 9-inch bearing housings) and 15x10-inch wheels with a 6.5-inch backspace are the A-plus combination for achieving a clean, tucked fit for 10.5-inch slicks on a mini-tubbed Fox. We haven't yet selected a wheel package for Boss 340, but we're strongly considering using beadlocks on whichever wheel we choose for the rear.

After delivering Boss 340 to A.R.E., we immediately put it in the air to assess the car's needs (for completion) and to develop a strategy for the build process. As we learned with the T-top car, full-build projects (street cars or racecars) require you have a solid idea of what you want or what you want to do from the outset, and then allotting a sufficient amount of time to get it or do it. Notice that our LX actually does have a front end (fascia and fenders), which was taken from the aforementioned parts car before it was junked. The Mustang may not look like much now, but our plan is to have a Boss-themed vinyl wrap designed and applied by the crew at Catalyst Imaging in Van Nuys, California, once we get this bad boy running and rolling under its Boss 340 power.