Читать книгу 1970 Chevrolet Chevelle SS - Dale McIntosh - Страница 8
ОглавлениеYou can see the open “flapper” of RPO ZL2 Special Ducted Hood Air system with “COWL INDUCTION” script. The flapper was vacuum-controlled and opened only under very low engine vacuum so it was closed when the engine was not running and open completely at wide-open throttle. (Ron Wawrinty Photo)
Chevelles of Generation One are from 1964 and 1965, due to their similarity in styling. Those of 1966 and 1967 were more forward looking and have a specific sport coupe roof line; they are considered Generation Two.
In 1968 and 1969 the Chevelle took on another new look with tapered front fenders, rounded beltline, and a long-hood/short-deck profile. All Malibu and Concours station wagon series in 1968 featured hide-away windshield wipers, but the Nomad, 300, and 300 Deluxe series did not. The rear of the hood had a small lip to help conceal the wiper arms/blades. The lower windshield trim was wider on the Malibu and Concours series so the wiper arms could “park” below eye level. The 1968 and 1969 vehicles make up Generation Three.
Because of its unique styling change from previous years, the 1970 model year is considered the beginning of Generation Four. These vehicles saw an updated design with more rounded corners and muscular stance. This was the last year Chevelles were equipped with separate low- and high-beam headlamps, a staple since 1964. The 1970 model year also separated the headlamps from the grille and the grille extensions outside the headlamps were gone.
Beginning in 1971 all Chevelles used a single headlamp for both low- and high-beam operation.
It was typical that prototypes and clay mockup mules were worked on about two years before the planned introduction of any new model year. The 1970 Chevelle was no different. Numerous designs were pored over. Although the overall profile was pretty much settled, styling tweaks were looked at. One early design feature has the Chevelle with a front end reminiscent of the new to-be-released Monte Carlo.
Headlights
Single, round headlamps on each fender along with round parking lamps were designed along with the now-familiar dual headlamps and rectangular parking lamps. Variations including single headlamps with rectangular parking lamps, and dual headlamps with round parking lamps were also mocked up.
In this early clay mockup of the 1970 Chevelle, dated January 15, 1968, GM styling used a single headlamp and round parking lamp design that was eventually used on the new-for-1970 Monte Carlo. (Photo Courtesy General Motors Media Archive)
This side-by-side front view shows both the rectangular and round parking lamp designs. The bowtie emblem in the grille of the “Malibu” on the left along with “CHEVELLE” lettering across the front of the hood is in contrast to the round parking lamp design and lack of hood lettering on the “Chevelle” on the right. (Photo Courtesy General Motors Media Archive)
This December 9, 1968, photo shows trim above the rear bumper to mimic the center cove of earlier model years. Hastily applied stripes extend to this proposed trim. (Photo Courtesy General Motors Media Archive)
Stripes
A few options also went through different designs and iterations. RPO D88 Hood & Deck Stripes were relatively narrow stripes that paralleled the hood and trunk lines a few inches inboard of the quarter panels, quite similar to those eventually used on the 1974 Nova SS. Another variation had the stripes in their now-familiar width and general location but extending to the grille and included extra horizontal trim reminiscent of earlier years above the rear bumper on the trunk lid.
Induction
One RPO ZL2 Special Ducted Hood Air System (cowl induction) design had a wider bulge and twin vacuum-operated flapper doors.
Even in these early designs, as early as 1968, the SS396 was to be built. When General Motors lifted the 400-ci engine for the 1970 model year, the SS454 option was added to the lineup. Other than a beefed-up driveline and 454 numbering on the front fenders, there is no visual difference between the SS396 and SS454. A few options such as air conditioning could not be ordered with the LS6 engine. The LS5 and LS6 engines were limited to either the RPO M22 Muncie 4-speed manual or heavy-duty TH400 Turbo Hydra-Matic 3-speed automatic transmissions.
This early mockup design shows the familiar dual headlamps and rectangular parking lamps. Of note in this photo are twin openings on the RPO ZL2 Special Ducted Hood Air system design, no stripes, and no hood pins that became part of the final option. (Photo Courtesy General Motors Media Archive)
The 1970 Chevelle SS Equipment options retained their performance-oriented theme. Several items were included in the RPO Z25 SS Equipment option, which included the base 396-ci engine rated at 350 hp and engine bright accents such as valvecovers and air cleaner lid (on non-ZL2 Special Ducted Hood Air System the hood in which the air cleaner lid was black regardless of the engine) The option also included power front disc brakes, dual exhausts, black-painted grille, wheel opening moldings, special domed hood, F41 heavy-duty suspension with rear sway bar on the Malibu sport coupe and convertible, and special 14×7 SS wheels with F70×14 white-letter tires. RPO F41 and rear sway bar were not available on the 13680 Malibu series sedan pickup when either SS Equipment option was ordered due to it being equipped with standard rear air shocks.
Here you see the air cleaner seal and blacked-out lid on RPO ZL2 Special Ducted Hood Air system on an LS6 engine. All LS6 engines were equipped with GM’s Air Injection Reactor smog system. (Photo Courtesy Rick Nelson, MuscleCar Restoration & Design)
This air cleaner seal and blacked-out lid on RPO ZL2 Special Ducted Hood Air system appears here on an L78 engine. Also note that all L78 engines were equipped with GM’s Air Injection Reactor smog system. (Photo Courtesy Michael Rothberg)
Another change from previous SS Equipment options was that the heavy-duty, floor-shifted, 3-speed manual transmission was no longer standard. You had to order one of the manual 4-speed transmissions or the TH400 automatic transmission. The SS396 owner could choose between the wide-ratio M20 or close-ratio M21 Muncie, and the SS454 was limited to the heavy-duty M22 Muncie for manual transmission.
All SS Malibus received the round pod dash; RPO U14 instrument panel gauges were optional. A black steering column and black steering wheel were standard on all SS Malibus. (Photo Courtesy Randy Valle)
Although the TH400 was only one RPO code, the engine dictated how strong a TH400 was received. RPO Z15 was the SS454 option that came with the same basic equipment as RPO Z25 with the exception of the 454-ci 360-hp engine instead of the 396-ci 350-hp engine.
All SS Equipment Chevelles received a round pod instrument panel instead of the linear (or sweep) instrument panel of a non-SS Equipment Chevelle. The base SS Equipment dash has three large round pods and three smaller round pods. Without the instrument panel gauge option the large three pods show the fuel gauge in the left pod, the speedometer/odometer (and automatic transmission indicator if column-shifted) in the middle, and a blank right pod. Above the headlamp switch on the left side of the dash is the generator lamp and on the right side of the dash above the radio are the water temperature and oil pressure warning lamps.
When RPO U14 was ordered (SS or not), the round pod dash was used. The three large pods (from left to right) included the tachometer (with oil pressure warning lamp), the speedometer/odometer (and automatic transmission indicator if column-shifted), and either a blank pod or a clock. An amp gauge occupied the top left small pod; water temperature and fuel level gauges occupied the two right-side small pods.
The tachometer was located in the former fuel gauge pod and had an oil pressure warning lamp built in. No oil pressure gauge was offered, which seems rather odd. Many enthusiasts were more concerned with oil pressure than with ammeter readings. RPO U14 could be ordered in any V-8 Malibu sport coupe, convertible, sedan pickup, or Monte Carlo, whether SS Equipment or not.
The tachometer code in box 72 is 938 on this LS5 Chevelle. It should be 985. This computer programming error was unique to the Atlanta assembly plant. The Atlanta, Georgia, plant was the only one to use the “MALIBU COUPE H/TOP” words on sport coupes.
Arlington, Texas; Baltimore, Maryland; Kansas City, Missouri; and Van Nuys, California, assembly plants coded the L34/LS5 tachometer in box 72 correctly as code 985. The Flint, Michigan, assembly plant did not use this form of broadcast sheet.
There is a lot of misconception about the optional gauges offered. Even SS Equipment Chevelles only came with a fuel gauge standard; gauges and a clock were optional. There is no such thing as “SS gauges.” There was one gauge option in 1970, RPO U14 Instrument Panel Gauges, and it came with an appropriate redline tachometer, an ammeter, and water temperature gauge. The 307- and 350-ci engines received a tachometer with a red-line at 5,000 rpm, both the base 396 and 454 engines received a tachometer with a redline at 5,500 rpm, and the optional 396 (L78) and optional 454 (LS6) received a tachometer with a redline at 6,500 rpm.
As a result, all documented Atlanta SS454 Chevelles with the base engine received the lower, 5,000 rpm redline tachometer. When RPO U14 was ordered there was a three-digit code on the build sheet indicating which tachometer the car should receive. These three-digit codes are 938 for the 307 and both 350-ci engines, 985 for the base 396/454-ci engines (L34/LS5), and 983 for the optional 396/454-ci engines (L78/LS6). Unfortunately, Atlanta had programmed its computers in error, so when an LS5 SS454 was ordered with RPO U14 it received the 307/350-ci engine 5,000-rpm redline tachometer, code 938, instead of the 5,500-rpm redline tachometer it should have received.
This July 1, 1970, Atlanta, Georgia, build sheet shows RPO U14 IP GAUGES but not the RPO U35 clock. The clock was only standard on the Monte Carlo with or without RPO U14 IP GAUGES optional gauges.
