Hey John, I found the story that Hemmings ran in 2011 on my car so I thought I would share it with you, it has lots of info I think you would be interested in. Sam
Buyer's Guide from Hemmings Muscle Machines
Something happened on the way to 1969. The car-buying audience, which had lustfully purchased full-size cars equipped with an array of big-block power earlier in the decade, had shifted their attention to the new beauties on the street. The intermediates had evolved into nice, tight little packages: more power, less weight, racy trim and you could still bang gears just like the NHRA regulars. Better yet, you could still pack a couple of friends into the cabin with you. But that didn't mean that full-size muscle cars were completely out of the picture.
In keeping with a long-standing tradition at Chevrolet, the division continued to offer a performance package option on a portion of its 1969 Impala lineup; it would later prove to be the last such incarnation for the next 25 years. Called SS 427 in Chevrolet literature, it was a straightforward deal costing buyers an extra $422, which provided meaty wheels and tires, a more sinister blacked-out grille, a healthy Mark IV big-block under the hood and badges to match. Perhaps in a sign of the times, the '69 Impala SS proved a rarity on the streets: just 2,455 were built, including this month's subject, a well-optioned Custom Coupe edition owned by John Martin of Louisville, Kentucky.
Unlike other performance rarities, however, there's good news for the fans of '60s muscle: The final Impala Super Sports do not command a massive entry fee. In terms of average sale prices, even the most powerful of the breed is more affordable than a 396-powered, same-year Chevelle SS. If that sounds interesting, here are the details on Chevy's last full-size performance car of the original muscle era. ENGINES
It should first be noted that it was possible to obtain a non-SS Impala with a 427-cu.in. engine, although that V-8 carried an advertised rating of 335hp. Meanwhile, the SS package offered considerably more power, even in base form, with the L36-code 427, rated at 390hp at 5,400 RPM and 460-lbs.ft. of torque at 3,600 RPM. For all intents and purposes, it was the same engine that had been offered for the previous two years in the performance Impala. Those 427 cubic inches were the result of a 4.25-inch bore and 3.76-inch stroke, and the L36 version also featured 10.25:1 compression, a hydraulic lifter camshaft and a cast-iron crankshaft held in place by five two-bolt main bearing caps. In addition, the cast-iron intake manifold was outfitted with a Rochester Quadrajet carburetor, and the cylinder heads contained 2.06/1.72-inch intake/exhaust valves; a dual exhaust system helped the big-block breathe.
As good as the base engine sounded on paper, missing from dealer literature available to the casual window shopper was a more powerful Mark IV. Offered under sales code L72, it boasted 425 horsepower and a redline in the area of 6,000 RPM. Major differences between the two engines were the L72's 11.0:1 compression, solid lifters and forged crankshaft, along with an aluminum intake capped by a 780-CFM Holley four-barrel carburetor. To increase strength and durability, the block made use of four-bolt mains. Breathing was improved, too, thanks to square-port cylinder heads containing larger 2.19-inch intake valves.
Vintage Chevrolet Club of America member Steve Leunig--who specializes in 1965-'69 full-size Chevys, as well as the division's big-block engines--told us that minor teething issues had been solved long before the 1969 engines were issued, meaning that as a whole, they are very reliable. In addition, OE-spec and aftermarket components are available, allowing experienced do-it-yourself mechanics to rebuild the 427 with relative ease. TRANSMISSIONS
As in previous years, each Impala SS was originally intended to be delivered with a column-shifted three-speed manual, except that this unit was of the heavy-duty variety--to cope with the 427's output--with a 2.42:1 low gear. As was often the case with muscle cars, buyers usually passed over the three-speed in the Impala SS in favor of either the optional column- or floor-shifted Turbo Hydra-Matic 400 automatic, or a floor-shifted four-speed (either the wide-ratio M-20, close-ratio M-21 or heavy-duty close-ratio M-22).
Each of these units is quite durable and rarely fails under pressure. Yet lack of maintenance by a previous owner, or excessive abuse, can lead to problems. Fortunately, rebuild kits are plentiful, and experienced specialists can rebuild each with ease. That said, a few transmission-related parts are Impala-specific, such as the THM-400 console indicator plate; it's not being reproduced as of this writing. Look close and you'll notice that our feature car sports a Powerglide's plate--the Powerglide was not offered in conjunction with Mark IV big-block Impalas in 1969. DIFFERENTIAL
"Every SS edition in '69 received the 8 7/8-inch heavy-duty 12-bolt with a standard ratio of 3.31:1, with or without air conditioning," said Steve. He added that there was a full range of optional final-drive ratios--from economy-minded to launch-off-the-line performers--as well as the optional Posi-traction differential; our feature car contains a 3.73:1 ratio. No matter the gearing, it's important to remember that the unit as a whole is highly prized by racers due to its tremendous durability; of all the mechanical systems under the Impala sheetmetal, it's likely the last piece to fail. For parts scroungers, plenty of non-SS full-size Chevys also used the 12-bolt for 1969. FRAME
A carry-over from the 1967-'68 generation of the Impala was the continued use of a boxed perimeter frame with 119 inches between the wheel hubs; the front and rear track also remained unaltered, at 62.5/62.4 inches respectively. Despite this, Steve cautioned that the frame below the body of an East Coast example can have flaws.
"They can get very soft behind the front wheel openings, right where it curves down to the rockers. Also, check the length of the frame behind each rocker panel; this is the area where rot will actually penetrate the thickness of the steel. One last area to check is the crossmembers. The reason for all of this is that these sections of the frame are boxed; it's designed in a manner that catches grime and debris, preventing proper drainage. What many might find surprising is that the back third of the frame, especially behind the rear wheels, tends to ward off rust; this is the section that is not fully boxed, which means it has ample opportunity to dry out and remain debris-free." SUSPENSION
Full-size Chevrolets had been riding on the same chassis configuration since the 1965 model year, using coil springs all around, with upper A-arms and lower control arms up front and a three-link trailing-arm system with a Panhard bar in the rear of standard models; heavy-duty models used four trailing arms (usually in conjunction with the 12-bolt axle). Dealer literature, however, states that the SS 427 option automatically provided owners with a "special suspension." More specifically, this was the F40 package, which included heavy-duty front and rear hydraulic shocks, springs and a larger front anti-roll bar, not to mention provisions for larger wheels and upgraded brakes. Rebuild parts to freshen the whole system are readily available. BRAKES
No need to worry about swapping out an archaic drum-brake system with the '69 edition of the SS 427 package: It mandated the installation of what would otherwise be an optional power disc/drum brake system that used 11.75-inch vented rotors with single-piston calipers at the front end. Self-adjusting 11 x 2-inch drum brakes were fitted at the rear axles.
Lack of replacement brake parts should no longer be a concern; everything from OE drums and rotors to wheel cylinders and brake lines are now available. Several companies offer aftermarket front and rear disc brake conversion kits at reasonable prices. When shopping for such a kit, be sure to check wheel size requirements.WHEELS & TIRES
The aforementioned F40 suspension also required assembly line employees to install larger 15 x 6-inch wheels, which were shod with G70-15 red-stripe bias-ply tires. Each wheel was presented with a standard hub cap, although buyers had their choice of two different full wheel covers--designed to accommodate the cooling requirements of disc brakes--or the more popular ZJ7 option: Rally wheels measuring 15 x 7 inches with center caps and trim rings. BODY & INTERIOR
Chevy limited the SS 427 package to just three Impala models: Custom Coupe, Sport Coupe and the convertible. Each had been the recipient of a redesign for the model year, which lengthened the overall body dimension to 216 inches. It was just an increase of one inch from the previous generation; however, the front end was vastly different, fender lines were updated and the rear section was reworked. Aside from an obvious SS badge, the new recessed quad-headlamp grille was blacked out, helping differentiate it from the rest of the Impala fleet; another SS badge was centered on the trunklid.
Yet even within the SS package, there were subtle differences with regard to fender markings: Both the Sport Coupe and convertible received "Impala SS" emblems, while the Custom Coupe received just the "SS" emblem on the fender, which was supplemented by the "Impala Custom" emblem on the C-pillar. As with other cars of the era, Steve cautioned that rust could be an issue here, mostly, "At the base of the front fenders, rocker panels and around the rear wheel openings."
Inside, the SS package no longer meant that a pair of bucket seats and a center console automatically greeted owners. Both had to be ordered off the option chart, and as a point of interest for those looking at a potential restoration project, the center console as a whole is identical to those used in 1968 models. The lone indication that you were indeed inside an SS Impala was the single badge affixed to the steering wheel. Upholstery within the hardtops was a combination of patterned cloth with vinyl, while convertibles received more weather-resistant vinyl seats; all-vinyl interiors could have been ordered in hardtops as well. New-for-'69 interior features included a locking steering column and a neutral safety switch. RESTORATION & PERFORMANCE PARTS
Mechanically speaking, it's likely that there will never be a shortage of Chevy parts, even for these full-size performers. That includes everything from OE-style suspension bits to something as simple as a pushrod for the 427. Add to that the ever-increasing popularity of aftermarket engine, brake and suspension upgrades, and you have a great potential project. One area that is deficient (at least for the time being) is reproduction sheetmetal. Currently, full floorpans, floor braces, and trunk sections can be obtained, as can rocker panels. However, as of this writing, only fender and quarter patch panels are available.
While it may seem obvious that a full-size car should have a full-size engine, you'll be happy to see a 427-cu.in. V-8 when you pop the hood. Two were available: the base 390hp L36, and the rather rare and highly desirable 425hp L72. Brakes
No need to look for stock Chevy disc brakes in your local boneyard, since the 1969 SS 427 Impalas mandated the system's installation at the factory. Of note, Chevy switched from multi-piston to single-piston calipers for '69. Transmission
Even though the Turbo Hydra-Matic was an option, it's probably the most common transmission found backing the 427 in 1969. Bear in mind that it is possible to find one equipped with a standard three-speed manual, or one of three four-speed gearboxes. Interior
Unfortunately, the SS package did not upgrade the buyer to Strato bucket seats, as in years past, but they could still be ordered, along with a center console, choice of radio, air conditioning and a litany of other luxury items. Chassis
Chevy's full perimeter frame was essentially unchanged from the previous year, which included its problem areas. Keeping the Impala glued to the pavement was the standard F40 heavy-duty front and rear suspension system. Body
Whether it's the Custom or Sport Coupe, or the convertible body style, restoring the exterior sheetmetal might be a little problematic due to a lack of full reproduction panels. Several trim items, such as emblems, are more plentiful.
My first car was a 1966 Impala SS; it was a 390hp 427/four-speed car with 24,000 original miles that I purchased from the original owner. I rebuilt the car and drove it through high school and college, only to have it stolen in 1999. My passion for the B-body Impala had me looking for a replacement, even though I had owned two Corvettes and a 1970 Ram Air III Trans Am.
When I found this '69, it was listed for $600, less engine and transmission. I was able to discover that I had purchased an L72 car, and during its restoration, I was able to trace the Impala back to the dealership that sold it, and the original owner, who verified its build.
I responded to an ad in Hemmings Motor News for a 427 engine that I later discovered was not only an L72, but also a rare CE code (counter exchange, or warranty replacement), which is essentially treated as if you have the original block by Chevy judges.
The Impala is a joy to drive with my kids; they like the acceleration when it pushes them back in the seat. It doesn't get noticed driving down the road as much as it does crackling through a parking lot or at a stoplight; the raspy idle grabs anyone who knows about muscle. -- John Martin
CLUB SCENE National Impala Association
5400 43rd Ave S
Minneapolis, Minnesota 55417
Dues: $35/year • Membership: 2,600 Vintage Chevrolet Club of America
P.O. Box 609
Lemont, Illinois 60439
Dues: $35/year • Membership: 8,000
WHAT TO PAY 1969 Impala SS
Low Average High
Custom Coupe $12,000 $21,000 $29,000
Sport Coupe $12,000 $21,000 $29,000
Convertible $14,000 $24,500 $34,500
Add: four-speed, 5%; air conditioning 5%
PARTS PRICES Brake drum -- $80
Brake rotor, pair -- $230
Cam gear -- $20
Carpet set -- $150
Emblem, fender Impala -- $110
Emblem, grille -- $90
Floorpan assembly -- $1,199
Front end rebuild kit -- $460
Molding, wheel opening set -- $210
Quarter panel, lower -- $127
Piston set, 427-cu.in. -- $561
Rocker arm set -- $135
Rocker panel, left -- $55
Taillamp lens, set -- $140
Weatherstrip, trunk -- $25
Wheel cylinder, rear -- $40
This article originally appeared in the October, 2011 issue of Hemmings Muscle Machines.
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