YF3 Registry

Guide to the 1971 Heavy Chevy

By 1971 both insurance rates for Muscle Cars were climbing and the federal government was beginning to get serious about emissions. Chevrolet saw an opportunity to keep the looks of a Muscle Car but also offer a wider variety of lower horsepower engines to satisfy insurance agents. While the SS Equipment option continued in the Malibu series Sport Coupe, convertible, and pickup (El Camino), the base Chevelle Sport Coupe (13437) was offered with a dress-up option called the Heavy Chevy under RPO YF3. Just the fact you have a 13437 Chevelle Sport Coupe does not automatically make it a Heavy Chevy anymore that the fact you have a 13637 Malibu Sport Coupe make it a Z15 SS-optioned Malibu.

Looking at the individual items packaged with the YF3 option, there is nothing in there that could not be installed by a person in their own driveway to 'clone' a Chevelle Sport Coupe into a factory YF3 optioned Chevelle Sport Coupe.

Since the Heavy Chevy was based on the base 13437 Chevelle Sport Coupe only and the amenities were austere to say the least. Since bucket seats were not an option available on the base Chevelle series, bucket seats could not be ordered with the Heavy Chevy option either. Interior fabrics and colors were restricted as well. The YF3 option was a 1971 mid-year offering (March, 1971) and there was no promotion of the option to the public. A salesman's supplement announced the option to dealers and it was up to them to promote the cars. As a consequence only 6,727 were sold in 1971 in the U.S.  but the number climbed to 9,508 in 1972.

As with non-SS and SS-optioned Malibus, two dash assemblies were available. The basic sweep-style speedometer with fuel gauge was standard and a clock was optional. The round-type dash pod was used when RPO U14 Instrument Panel gauges were ordered. The gauges were identical to those offered in the Malibu series and included the speedometer, tachometer, fuel, water temperature, ammeter, and clock. The oil pressure indicator remained a warning lamp and was housed in the tachometer.

The YF3 option included not only the wild laser stripes down both sides but "Heavy Chevy" decals on the front fenders, on the trunk and hood as well in lieu of the typical "Chevelle by Chevrolet" emblems. Other items included in the YF3 option were a black accented grille, special domed hood with locking pins, 14"x6" rally type wheels with special center caps. Stripes were only available in black or white and noted under Model Options on a March 1, 1971 spec sheet, stripes were not available when vinyl roof cover or when black or white painted roof is specified. Why these three limitations would be imposed is a mystery. Not sure what would happen if a black car were ordered with a white vinyl top.

YF3 Registry


The Heavy Chevy could be ordered with any V8 engine except the LS5, 454 cubic inch V8. The Powerglide transmission was only available with the 307/200hp engine while the two 350 engines (L65 & L48) got the Turbo-Hydra-Matic 350 and the 402 engine (LS3) got the Turbo-Hydra-Matic 400 and all were column-shift units along with the standard 3-speed manual transmissions. The optional manual 3-speed and manual 4-speed (M20 wide ratio) was available behind any of the three optional V8 engines as a floor-shift unit but no consoles were available in the Heavy Chevy since that would require bucket seats which were not an option.

Standard Interior Equipment

Only black cloth (701), black vinyl (703), dark blue cloth (724), and dark jade cloth (736) interior colors/fabrics were offered. Floor covering consisted of a color-keyed vinyl-coated rubber mat in lieu of carpeting & no trunk mat was supplied. Glove compartment and courtesy lamps were not standard equipment but could be ordered via RPO ZJ9, Auxiliary Lighting equipment.

Door panels were sparsely attired in the Chevelle Sport Coupe and the Heavy Chevy option did nothing to dress these up.  The 1971 model year door panels were color coordinated with the interior and featured raised panels and an ivory white stripe.

1971 Heavy Chevy Door Panelsl - Courtesy Ron Brundies
1971 Heavy Chevy Door Panelsl - Courtesy Ron Brundies
Note the raised panels on the original top door panel compared to these aftermarket offering with flat panels.

1971 Heavy Chevy Door Panelsl - Courtesy Ron Brundies
1971 Heavy Chevy Door Panelsl - Courtesy Ron Brundies
The same holds true for the rear panels, original has raised areas where these aftermarket units are flat.

File Photo - 12/10/2012
Only the 1971 Nomad series (131-13236 series) shown above had plainer door panels. Note door panels carry the same design but without the white stripe.

Exterior Equipment

Standard exterior trim was as austere as the standard interior trim. The grille did not get the center bow tie emblem but the Heavy Chevy did get the grille outline moldings the standard Chevelle did not. The lower windshield reveal molding was narrower than the Malibu & the windshield wipers did not depress below the windshield and not have an articulated left blade. Bright wheel opening, rocker, and roof drip moldings were also absent although two-tone and vinyl-topped Heavies did get the normal trim separating the body and roof. The tail lamp lenses were a plain red and red/white lens without the bright trim rings or Argent Silver paint.

With the YF3 option, the typical "Chevelle by Chevrolet" emblem on the deck lid was removed in favor of the "HEAVY CHEVY" decal. The build sheet will note this "deletion" with RPO BW1 DELETE RR MLDG, BW1 RR END ORD DEL or such verbiage depending on the assembly plant.