OPGI Spotlight Newsletter Volume 1, Issue 3 Colin's Corner

Sweet Chevelle

A showroom stock, ready to rock ’66 Chevelle gets put back better-than-new!

1966 was a year of big changes in automotive styling, and Chevrolet’s iconic Chevelle brand was certainly no exception. FoMoCo had axed the boxy Fairlane look for good, finally putting that car on a sleek new platform. Even the Mopar camp had taken their somewhat bizarre Coronet and Belvedere line to new eye-catching levels by doing some serious streamlining.

Yes, if you were around in ’66, you were eyewitness to a dramatically altered automotive landscape - and I mean that in a good way! Even if you’re a diehard fan of the boxier “first” Chevelles (1964-’65), there’s no denying the all-new ’66 was a complete stunner. Aerodynamic “Coke bottle” styling, fresh new grille and taillights, and a very distinctive C-pillar with a wind-swept design on the SS models created a package that buyers couldn’t resist.

Four series of Chevrolet’s mid-size were available: Super Sport 396, Malibu, Chevelle 300 Deluxe, and Chevelle 300. Twelve models were spawned out of this series too - convertibles, sport coupes, wagons, and 2 and 4-door sedans. How does that compare to today’s Malibu line-up? Well, never mind...

Want a little more variety? How about a choice (depending on the model you select) of 3 different “standard” engines? The 120 horse Hi-Thrift 194 cubic-inch Six, the 195 hp Turbo-Fire 283 V8, or the 325 horse Turbo-Jet 396. Then of course, there was the “optional” engine line-up. Extra cost engines included the 140 horsepower Turbo-Thrift 230 cube Six, the 220 horse Turbo-Fire 283 (V8), the 275 hp Turbo-Fire 327, or the top-of-the-heap 360 horse Turbo-Jet 396. Today’s Malibu has, well, two engine choices. That’s not to demean Chevy’s current mid-size in any way; it’s just to illustrate how things were more than a tad different 44 years ago.

In addition to all those engine choices for 1966, you could select from 4 different transmissions as well. The standard tranny was a fully-synchronized 3-Speed manual unit. Extra cost optional trannies included a full-sync 4-Speed (floor mounted), an Overdrive automatic, or the legendary Powerglide -a three-element torque converter with hydraulically controlled 2-speed planetary gearing (P-R-N-D-L).

The top-of-the-line Chevelle for ’66 was, of course, the legendary Super Sport 396. You could order this beast in Coupe or Convertible form. Standard firepower with this model was the 325 horse Turbo-Jet 396 cube V8, with the manly 360 hp 396 being optional. With either engine, the 3-Speed tranny/floor mount shifter was base equipment. The 4-Speed (floor mount shifter) and Powerglide were both optional.

On the outside, all Super Sports got distinctive non-functional louvered hood “scoops”, polished stainless steel moldings on the wheel openings, sill area (rockers and rear quarters), as well as unique SS 396 badging.

Ah, the glory years of interiors! Yes, when it came to color choices inside the SS396, you could go hog wild. Eight color choices were on the list for ’66: Red, Blue, Black, Bronze, White, Bright Blue, Fawn, and Turquoise. Front and rear seatbelts were standard. Interiors were all-vinyl. Originally, our CC feature car sported a White interior, but was changed to Two-Tone Turquoise by the OPGI crew.

Strato-bucket seats are the perfect complement to a fully-loaded interior featuring floor console, Sports Styled Steering Wheel with Simulated Walnut, Power Windows and Air Conditioning.

The big bad 360 horse 396 - the top offering for Chevelle for 1966. This particular motor is the original unit, and it’s been meticulously restored by OPG’s Sales Manager James Ferguson.

The 360 hp Turbo-Jet 396 features a 4-barrel carburetor, chrome-plated rocker covers, air cleaner, and oil filler cap.

Cast aluminum pistons • 10.25:1 compression ratio • 4.094 x 3.76 (bore and stroke) • 360 hp @ 5,200 rpm • torque: 420 ft.lbs. @ 3,600 rpm

Inspection of differential housing and gear set

In this short tech, we’re going to cover how to inspect your car’s differential housing and gears, not a total rebuild. You won’t need a lot of tools for this job, just a standard socket set, flat-blade screwdriver, and a hammer or mallet. Your “tinware” will include new gear oil, clean rags, a container to collect the old oil, and a new differential cover gasket.

Let’s face it; it’s easy to neglect routine maintenance needs of your car’s rear axle assembly.

Unless there is some horrific sounding grinding coming from back there, the differential fluid level is probably good and clean. An easy-to-believe scenario, but not entirely accurate. True, the rear end components are pretty tough, but even they need to be cared for. When you think about the extreme loads that are being placed on the differential and rear axles, it’s pretty easy to realize that in time, breakdown is inevitable. Preventative and periodic maintenance can go a long way!

A totally ignored rear end assembly can cost you more than money, it can cost power too. Posi-traction units will loose much of their effectiveness, and open ended diffs can become utterly useless. All the engine power in the world does you absolutely no good if the rear end is unable to deliver that power to the drive wheels. And in order to do so, everything must be in perfect working order. If you suspect problems, or maybe you can’t remember the last time the gear oil has been changed, it’s definitely time for a routine inspection and clean-up.

First off, the rear differential cover must be removed. Using a shop hoist is best, or, if you don’t have access to one, use a floor jack and jack stands. The object here is to safely raise and secure the rear of the vehicle—allowing access to the cover bolts. You’ll need to have some type of container in position to catch the gear oil from the bottom of the housing once it’s removed. Then, remove the retaining bolts from the diff cover, starting with the bolts near the top of the diff cover. After the bolts are removed, it may still be necessary to pry the cover along the edges away from the housing. The thick, rear-end gasket can create a pretty tight bond between the two surfaces. Go easy, being careful not to bend the sealing area of the cover plate.

Once the cover has been removed and the fluid drained, you’re going to inspect the inside of the housing for any built-up sludge. Use a shop light or a strong flash light to really see what’s going on in there, and remove the sludge (usually found at the bottom of the housing) with some clean rags. Commercial cleaners in the form of spray cans also work well for dissolving old residue and oils.

Now, this is where you’re going to have to have a sharp eye. Closely examine the teeth of the gears for chipped edges or cracking. One side of the ring gear may show excessive wear. This usually indicates sloppy gear engagement and operation. If the teeth appear to be damaged, you should replace the gear set. If you can tackle this yourself, great. If not, go see a quality shop and have the work done. If you decide to do the job on your own, Original Parts Group has everything you’ll need to get the job done properly. From new ring and pinion sets to complete differential units and rebuild kits, OPGI has it all for your GM-A Body. If you need advice, give one of the OPGI sales technicians a call, they’ll be able to answer any questions you may have.

If however, after a thorough inspection and cleaning, your gears appear OK, install a new diff cover gasket and your cover plate. Torque the bolts down evenly to the manufacturer’s specs. Refill the case with quality gear oil and check for leaks.

CC’s first quiz:

In the first installment of Colin’s Corner, I mentioned that there might just be the odd quiz now and again. Well, here’s the first one. This one’s a GM “general knowledge” type quiz – nothing too earth-shaking or mind bending, but there still may be a few that’ll trip you up. I’m not going to supply the answers here – that would just lead to “no cheating on this test!” Hey, relax, it’s not a test. Just something to have fun with – maybe something you can share with your buddies – you know, the ones who claim to know it all! I’ll supply the answers next CC. Have fun, and try not to use the internet to dig up all the answers!

1. What was the last year the “Chevelle” name appeared on a Chevrolet?
2. Which 3 GM divisions utilized front wheel drive during the 1960s and 1970s?
3. What was the largest available engine (from the factory) in the 1970 Camaro?
4. What do the numbers used by Oldsmobile “4-4-2” stand for?
5. What was the first year the Impala hit the road?
6. What year did Pontiac’s GTO become its own model, and not just an “option” on the Tempest?
7. When did the name “Stingray” cease to appear on the Corvette?
8. What year did the first “boat tail” Buick Riviera appear?
9. What was the last year Cadillac produced a convertible? (Modern day Caddys and modified/concept cars do not apply here!)
10. For which model year was the Monte Carlo introduced?
11. When did the first “Heavy Chevy” model arrive on the scene? And which Chevrolet model was it based on?
12. What do the letters “GTO” stand for?
13. What model year was the 350 cubic-inch V8 introduced in Chevrolets?
14. In 1968, what was the maximum allowable cubic-inch displacement for the A-body line-up, as dictated by GM Corporate?
15. What was the first year Pontiac utilized the front “soft nose” urethane bumpers?
16. What was the model name given to Oldsmobile’s “glass paneled roof” Station Wagons during the ’60s and ’70s?
17. What was the last year for side vent windows on GM A-body vehicles?
18. In 1970, which GM division produced the “Rallye 350”?
19. What do the words “El Camino” mean?
20. What was the name of the Chevrolet/Pontiac “half-breed” A-body produced by General Motors of Canada during the 1960s?