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.