My '65 Formula S Data Sheet

Fender Tag Decode

1-1 left manual outside mirror
3-9 variable speed wipers w/washer

AB-31 273 V8 4bbl
C-2 Barracuda Formula S Package
D-5 Automatic Transmission
E-1 Air Conditioning w/Heater
F-1 Power Brakes
Q-1 AM Music Master Radio
T-8 Tachometer
V-3 Back-up Lights
X-8 Retractable Seat Belts Front & Rear
Z-2 Front Bucket Seats & Console

SO NUMBER
121 00054

1 = January; 21 = Day of Month; 00054 is Shipping/Sequence Order No.

BDY
V89
V = Barracuda V8; 8 = Barracuda; 9 = Barracuda

TRM
P4Y
P = Premium Front Bucket Seats; 4 = Vinyl Bucket Seats;
Y = Gold Seats, Headliner, Carpet

PAINT
WW1 A
W = White Roof; W = White Body; 1 = Mono Color;
A = Inside Door Color Gold

Modifications by Previous Owner(s)

The original factory 273 cubic inch block was replaced by a later and larger displacement 318 cubic inch block. The factory original 1965 single plane four barrel intake manifold was replaced by a similar factory 1966 single plane four barrel intake manifold that uses different fasteners (bolts) and a different fastener hole angle.

The factory 273 original oil pan was replaced by a later 318 oil pan that interfered with the steering link (the steering link was beginning to wear a hole in one side of the oil pan).

The swapped in 318 block retained the special 1965 Commando 273 finned valve covers, Carter AFB carburetor, and chrome air cleaner. The exhaust manifolds are the factory stock versions for the small block motor used in a 1965 ABody like all Barracuda and Valiant models used at the time. Heat riser valve has been removed.

The Torqueflite automatic transmission is original to the vehicle and can be verified by the stamped numbers on the case which indicate it applies to a 1965 Commando 273 drivetrain.

Many of the A/C components have been removed and lost (condenser, compressor, brackets, pulleys, fan shroud, and under dash outlet vent assembly. Still intact is the A/C style heater box, receiver dryer, a couple of hoses, and dash switches. Unsure if installed six-blade fan is correct for this A/C equipped vehicle.

Other missing components: battery, correct gas cap, AM radio, windshield washer, dual point distributor (single point installed), “Commando 273” pie tin for air cleaner, spare tire and jack, differential pinion snubber, keys, hood insulation, factory wheels, “Barracuda” logo letters for trunk, factory exhaust manifold gaskets with heat shields (were replaced with non-shielded gaskets).

Factory in dash tachometer not working. Speedometer cable snapped (and speedometer locked up). Front windshield cracked. Trunk hinges broken.

Extra components found in trunk: right and left grilles with turn signals.

Gold interior was replaced by another Barracuda black interior (front bucket seats, rear seat, door panels). Therefore, build sheet found under the rear seat cushion is incorrect for this vehicle. However, the factory correct fender tag had been retained.

Factory wheels and wheel covers replaced by factory 14” x 5.5” Rallye wheels which were available on later models from 1970-1977.

The smaller, weaker, and lighter factory original 7 1/4” ring gear differential was replaced by the larger, stronger, and heavier 8 3/4” ring gear differential with casting number ending in “489”. Although sure-grip was optional on both, the installed differential is an “open” type (without the sure-grip feature). Rear end ratio is apparently 2.93.

New Owner Modifications (me)

The vehicle was purchased in a non-running condition. One piston in the 318 block was found to have a hole burned directly through the center of it. The engine received a stock 318 rebuild at Midway Engine Rebuilders on Market Street in Salinas, California. Block overbore is 0.040” which raised the displacement from 318 to 324 cubic inches. The cylinder block casting date is stamped as 12/4/79 (probably originally used in a 1980 model vehicle). Original motor mount brackets were modified to better match the newer block ears. Crankshaft is now cast (versus 273 stronger forged crankshaft) The cylinder heads are now open chamber (versus 273 closed chamber) with casting number of 2843675. The original Carter AFB carburetor was rebuilt by a local speed shop owner. Camshaft is now stock profile 318 hydraulic lifter version probably with specs .373/.400 240/248.

Block repainted factory red and valve covers repainted factory crinkle finish black. Body stripped and sandblasted and rotisserie restored. Cowl area rust damage restored and sheet metal replaced in front floors, trunk floor, lower quarter panels. rear window edging. Undercoating removed and not replaced. Acrylic enamel one-stage finish in factory original white (outside, inside, underhood, and underside). Factory style gold striping painted over the white acrylic enamel finish.

The gas tank was found to be punctured and was replaced. The factory stock radiator was rebuilt. The differential had a “dent” in the rear center but was not perforated and has not leaked any gear oil. A right rear wheel bearing was dry/grinding and was replaced. The factory style “ball and trunnion” style universal joint on the front of the factory driveshaft was changed over to a conventional u-joint. The transmission crossmember was modified on the passenger side to allow for installation of a complete TTI 2 1/2” dual exhaust system with turn down tail pipes. Cracked windshield was replaced. Distributor is now aftermarket/electronic Pertronix unit. Brakes replaced and power brake booster rebuilt by outside vendor (now after 10 years power brake booster has failed). Correct ’65 Abody oil pan installed. Fan shroud fabricated. Mechanical oil pressure and coolant temperature gauges installed. Dash circuit board replaced and factory mechanical volt limiter replaced with electronic unit. Factory ammeter now bypassed. Tachometer sending unit replaced with electronic version. Dash pad recovered and front bucket seats recovered (both in “camel” color). Headliner replaced. Cardboard factory glove box liner now fabricated from stainless steel. New brake master and wheel cylinders. New parking brake cables. New body gaskets and seals all around.

The transmission (at first) performed satisfactorily but ultimately rebuilt in Mexico (now leaking fluid front and rear seals). When re-installed, an adaptor bushing was purchased and installed to better match a 1968+ crankshaft to a 1960-67 Torqueflite 904 torque convertor.

New shock absorbers installed (rear shocks now have aftermarket extensions due to leaf springs having been modified with an extra leaf on both sides compared to factory springs). New differential pinion snubber fabricated. Front suspension retains stock torsion bars and stabilizer bar. Front brakes have automatic adjusters and rear brakes are manual adjusters.

Mopar Rallye wheels (without trim rings) re-painted “graphite” color and tires installed.
front: P185/75R14 Sears Guardsman Plus 24.9”/7.3” (“new”)
rear: P215/70R14 Hankook Optimo H724 25.9”/8.5” (used)

Since the current engine is a 318 LA block, it no longer uses the 273 Commando camshaft profile, the solid valve lifters, adjustable rocker arms, or the dome pistons (or the dual point distributor as mentioned above). For reference, a Plymouth/Dodge V8-318 2-bbl was factory rated 230 HP @ 4,400 rpm and 340 lb-ft torque @ 2,400 rpm with 9.0:1 compression ratio and bore and stroke of 3.91” x 3.31”.

Current problems: bucket seats still require old foam replacement, speedometer and speedo cable out of service, transmission leaking ATF, power steering leaking fluid, brake booster defective, turn signal not cancelling itself after left turns. Carburetor choke is tied open and accelerator pump weak. Ammeter bypassed to avoid shorts/fire.

Differential Tutorial

1-7/8″ tapered stem pinion… (aka. ‘489’)…
Carrier casting numbers: 2881488, 2881489 (1969-1974). This assembly was introduced in 1969 and was phased-in to relace the 1-3/4″ unit through 1970. Note: the 1-3/4″ pinion also appeared in some ‘489’ carriers during this period. By 1973, the ‘489’ was the only unit available in passenger car applications. This assembly was typically used in high weight/medium horsepower applications through high weight/high horsepower applications. Pinion depth is set with shims, preload is set with a crush sleeve. Differential bearing setting (ie. backlash ) is set with threaded adjusters.

All 8-3/4″ carrier assemblies can be identified externally by the casting numbers. Additionally, the ‘741’ commonly has a large X cast on the left side, the ‘742’ may have a large 2 cast on the left side, and the ‘489’ has a large 9 cast on the left side. Through 1965, the factory ratio was stamped on the identification boss, followed by an ‘S’ if Sure Grip equipped. After 1965, a tag was affixed under one of the carrier mounting nuts to identify the ratio. If Sure Grip equipped, an additional Sure Grip lube tag was sometimes affixed; later years sometimes had the filler plug painted orange.

Gear ratios available on the 8-3/4″ axle through the years include: 2.76, 2.93, 3.23, 3.31, 3.55, 3.73, 3.91, 4.10, 4.56, 4.89, 5.17, 5.57. On OEM gear sets, the ratio is usually stamped on the ring gear edge.