Car Craft
Click here to find out more!

1968 Plymouth Barracuda Formula S 340 - Homebuilt Road Racer

Regret Is Quelled While Corners Are Carved

Photography by

Like many car projects, Bob claims his Barracuda isn't actually done, ashe's still tweaking the suspension setup. Currently, the front rollcenter is around 3 inches while the rear is hovering in the 13-inchrange, which is damn good for a production sedan of this vintage, butBob thinks there's a little more refinement to be had. In the meantime,the Plymouth's street manners seem fully dialed, as evidenced by thetrip through L.A. traffic to our shoot location followed by a two-hourcruise back to Bakersfield. Once Bob can bring himself to subject RedHarden's paint job to a road course, the Camaros and Mustangs may be infor a surprise.

TECH NOTES

What: '68 Plymouth Barracuda Formula S 340

Owner: Bob Reed, a dentist by trade and road racer by choice

Hometown: Bakersfield, California, home of famous Famosa Racewayand Buck Owens

Engine: The original 340 block had already been built once, so ithad to be taken 0.040-over, though Bob's longtime friend and trustedrace-engine builder Hugh Reynolds of Reynolds Automotive Machine inBakersfield sonic-checked the cylinder walls first just to make surethere was plenty of meat. A cast 360 crank was turned down to fit the340 main saddles and then offset ground to create a 3.700-inch stroke.It works with custom JE pistons and Manley small-block Chevy-spec(gasp!) 6.3-inch rods to make 396 ci with 9.5:1 compression. A trickcustom oil pan fabbed by Tim Herren of Old Time Racing provides plentyof capacity and ground clearance, while adding baffling and trap doorsfor oil control.

Camshaft: A custom grind was ordered from Comp Cams on asolid-roller blank with 0.605/0.605-inch lift and 288/292 degrees ofadvertised duration. A 112-degree lobe separation angle was also spec'dto smooth the idle a touch since street driving was a big part of theplan.

Heads: A set of stock Chrysler "X" heads with 2.02/1.60 valveswas ported and matched to the intake manifold by Dick Landy.

Induction: That Mopar Performance M1 intake ported by Landy istopped with a Holley HP-series 830-cfm carb.

Exhaust: Off-the-shelf Doug Thorley A-body 15/8 headers fit thelowered Barracuda like a glove and connect to a Doug's 21/2-inch X-pipe,which feeds a pair of Dynomax Super Turbo mufflers. A pair of 21/2-inchTTI mandrel-bent tailpipes terminate with stock-looking chrome box tipsby Stainless Steel Exhaust Systems (Tennessee) that fit perfectly in thestock valence-panel cutouts.

Power: Reynolds Machine dyno'd the small-block Mopar and found521 hp at 6,500 rpm and 469 lb-ft at 5,200 on 91-octane pump gas. HughReynolds says that when run on race fuel with 41 degrees total timing,the horsepower rose to 547, though at the expense of lower-rpm output.

Transmission: The original iron four-speed was put on the shelfin favor of a Tremec TKO five-speed manual with overdrive (0.68:1)modified by Keisler Engineering to work with the Chrysler engine.Keisler also provided the offset shifter, driveshaft, and transmissioncrossmember to make the swap more feasible.

Rearend: The original 83/4-inch Chrysler axlehousing remains,along with its Sure-Grip differential, now spinning 3.91:1 gears.

Front suspension: Dr. Bob started by bracing the factory K-memberand then designed a way to modify the factory spindles to provide drop.He then had a chrome-moly tubular 11/4-inch front sway bar bent up,which "cost less than the available aftermarket bars and weighs about atenth as much." It's also adjustable thanks to Bob's fabricated mountinghardware. A Firm Feel Stage II steering box tightens up the inputs, andSpax adjustable shocks damper the Mopar Performance 0.920-inch torsionbars.

Rear suspension: Not wanting to cut the car, Bob stuck with astock leaf-spring rear suspension, which is currently using the originalFormula S springs enhanced with adjustable spring perches and an Addcorear sway bar hung from Bob's own adjustable hardware. More Spax shockshere as well.

Brakes: Bob replaced the front stock discs with 113/4-inchCordoba rotors clamped with aluminum four-piston calipers from The BrakeMan, mounted with Tim Herren-fabricated brackets. Out back, a readilyavailable disc conversion kit from Street Rod Manufacturing Company inCastle Rock, Colorado, bolted right up using late-'70s Cadillac-stylecalipers with an integral parking brake on custom-drilled rotors.

Body: The stock '68 Barracuda flanks were left unmodified, juststraightened and sprayed the factory shade of red by Red Harden ofCarriage Works in Bakersfield, California.

Interior: The interior was in great shape, but the stock frontseats don't offer much support, lateral or otherwise, so Bob contactedthe Seat Source in Long Beach, California, because this company offersthe unusual option of matching factory upholstery to aftermarket seats,like the Flofits used here.

Wheels/Tires: American Racing Torq-Thrust II wheels in 17x7 and17x8 are wrapped with Kumho Ecsta radials in 225/40-17 and 255/40-17 inthe rear.

Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
0 comments
Car Craft