1970 SS396/SS454
RPO Z25/RPO Z15 In General
This would be the final year for the SS396 as an option and it would only be available with the Malibu sport coupe, convertible, and El Camino series/body style.
The SS 396 engine actually displaced 402 cubic inches. GM had a lot invested in the "SS396" name that it was used in 1970 even though the engine size had increased. The manual 3-speed transmission along with the 325hp version were discontinued and only the 350hp L34 and 375hp L78 engines along with two manual 4-speed transmissions and the TH400 3-speed automatic were available. The L78 engine is relatively rare for 1970 since it was phased out of production around November with the anticipated introduction of the SS454 option and its 454cid engine.
The SS396 Equipment option included front power disc brakes, special 14x7 SS wheels, a domed hood and a round gauge panel with a fuel gauge and speedometer; warring lamps were used for oil pressure, water temperature, and amps. People often call these warning lamps 'idiot lights' but, think about it, how often do you scan your gauges while driving? A bright red warning lamp will probably catch your attention before you see a small needle move into a danger zone.
A bench seat was still standard fare for 1970 Chevelles, even when optioned with one of the two SS option packages. The Malibu sport coupe bench seat is a combination cloth and vinyl with an all vinyl seat optional at an additional $12.65. Both the Malibu series convertible and El Camino came standard with an all vinyl bench seat. Bucket seats and/or console were optional cost items. The gauge carrier, steering column, and steering wheel were black with both SS option.
The L89 aluminum head option was still an option with the L78 engine
only 18 were sold before the L78 engine option was canceled.
Since the 402cid L34 and 454cid LS5 were the base engines in the two SS option packages, they were not considered “options” as such and there are no published figures for the number of L34 or LS5 engines went into Z25 or Z15 Malibus. However, since the 402cid L78 and 454cid LS6 were optional engines and there are a known number sold, one can easily calculate how many Z25s were built with the L34 or L78 and how many Z15s were built with the LS5 or LS6.
Sales reports show there were 53,599 Z25 options sold in 1970. By subtracting the number of optional L78 engines (2,144) you can see there would be 51,455 SS 396 Malibus with the base L34 engine. Likewise by subtracting the number of optional LS6 engines (4,475) from the total number of Z15 options sold (8,773) you can see there were 4,298 LS5 powered Malibus - actually fewer LS5 Malibus than LS6 Malibus in 1970. The number of LS5 engines sold in Malibus DOES NOT includes the 3,823 LS5 engines sold with the Monte Carlo SS option; those are separate.
We are often asked by owners questions like, "How many LS6 convertibles were built?" Breaking any of the SS engines down by body style can only be done by a mathematically even calculation based on the number of each engine sold by each body style that could get the option. For example, first we must take the advertised number of Malibu sport coupes sold (289,622), Malibu convertibles sold (7,141) and Malibu El Caminos sold (40.728) and calculate the percentage of the SS454 option could have been ordered in a given body style. In the table on this page, the percentages and calculated numbers are done for both the SS396 and SS454 options.
The cowl induction hood, RPO ZL2, is one of the very few options one
could only order with one of the two SS options. While the RPO LS3 402cid
Mark IV big block was available in all non-SS Malibus in 1970, the ZL2
hood package was exclusive to an SS-optioned Malibu; no LS3-powered
1970 Malibu could order the ZL2 hood package.
Any exterior paint color and any interior color were available with any Chevelle within restrictions imposed by Chevrolet, such as a green interior in a red or blue Chevelle. Since both SS options could only be ordered with a Malibu sport coupe, convertible, or El Camino, any interior seat/material available for a non SS-optioned Malibu was also possible with the two SS options. No special colors or interiors were reserved for the two SS options.
RPO D88 stripes were optional on non SS-optioned Malibu sport coupes,
convertibles, and El Caminos as well as optional on both SS options
when the ZL2 option was not ordered. D88 stripes were part of the RPO
ZL2 package, along with hood pins, but could be deleted on request.
In this case the term “stripe delete” would be appropriate and the stripe
deletion required approval from the Fleet & Special Order office.
On an SS-optioned Malibu without the ZL2 option “stripe delete” is no
more appropriate than “radio delete,” “Positraction delete,” etc. If
someone did not order an option, it cannot be considered a “delete”
item.
Aside from the engine size the two SS options (RPO Z25 and RPO Z15)
were pretty much the same as far as standard equipment went. Both came
standard with front power disc brakes and F41 suspension. While the
Z25 SS 396 option could be ordered with either the wide ratio Muncie
M20 or close ratio Muncie M21 4-speed transmission or the M40 Turbo-HydraMatic
3-speed automatic transmission, the Z15 SS 454 option required either
the heavy duty close ratio M22 4-speed transmission or a heavy duty
M40 Turbo-HydraMatic 3-speed automatic transmission and did come with
a stronger rear end than its Z25 counterpart.
Both SS options came standard with a black dash carrier assembly, black
steering column, and black steering wheel with a centered SS emblem.
A “Cushion Rim” steering wheel was optional under RPO NK1 and this optional
steering wheel could be ordered with or without one of the two SS options.
The basic SS dash carrier gave the owner three large, round gauge pods
with fuel gauge, speedometer, and a blank along with three small gauge
pods for warning lamps for generator, water temperature, and oil pressure.
Optional, yes even on SS-optioned Malibus, was RPO U14 Instrument Panel Gauges. The U14 option included an ammeter, water temperature gauge, tachometer, and electric clock. The tachometer replaced the fuel level gauge in the large left-most pod, the speedometer/odometer remained in the large center-most pod, and the clock replaced the blank in the large right-most pod. An ammeter gauge was installed in the small left-most pod above the headlamp switch replacing the generator warning lamp; a water temperature gauge was installed in the small, upper right-most pod replacing the water temperature warning lamp; the fuel level gauge was moved to the small, lower-most pod replacing the oil pressure warning lamp. For some unknown reason, 1970 would see the end of an oil pressure gauge. The oil pressure warning lamp was retained but moved to the bottom of the tachometer face.
SS396 - RPO Z25 Unique
Two manual 4-speed transmissions were a choice with the Z25 option, the wide ratio RPO M20 and the close ratio RPO M21. The only automatic transmission offered was the 3-speed TH400. All L34cid SS396-optioned Malibus came with a 3.31:1 rear end gear ratio and Positraction was an option; all L78cid SS396-optined Malibus came with a 3.55:1 gear ratio.
SS454 - RPO Z15 Unique
One of two mandatory transmissions to choose from for the Z15 option, the manual 4-speed transmission was the close ratio heavy duty RPO M22 and the 3-speed TH400 automatic transmission. SS454-optioned Malibus came with a 3.31:1 rear end gear ratio and Positraction was an option. The 4.10:1 gear ratio (and the required Positraction) was only available with the L78 and LS6 engine options.
Ironically, the base LS5 engine was sold in fewer SS454-optioned Malibus than the LS6 engine. Of the 8,773 SS454 options sold, of those 4,776 opted for the LS6 engine resulting in
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1970 Chevelle SS396/SS454 Build Sheet Decode Program 1964-1972 Ship Manuals & Parts Catalog 1953-1972 Chevrolet Production Numbers |
