65 Chevelle SS Z16

[Steve Shauger]

These cars are unique in many ways, convertible frames, L37 396-375hp,
HD 1.06" front stabilizer. 160 mph speedometer, 11 inch HD brakes.
Although it was the ultimate performance 65 Chevelle, the package was not just performance oriented with luxury, items such as: tachometer, four-speaker AM-FM Multiplex stereo, dash-mounted clock, rear seat belts, instrument panel pad, and remote control outside mirror.

One item that seems odd is positraction was not included and the pedestrian 331 axle ratio.

Perhaps our resident expert Jeff Helms could chime in, since he is a walking, talking encyclopedia on Z16 and other chevelle models. Infact he owns a car, I always loved his red survivor Z16. He has a few other Z16's as well.

https://www.chevyhardcore.com/featur...bu-ss-396-z16/

[Lee Stewart]

[jeffschevelle]

Not too much I can add to the story (told many times) of the reason for the Z16 program! But I will address a few common misconceptions about the content of the option, and toss in a list of some of the special parts involved in the package.

First, there is often confusion about what was included in the Z16 package. The components that were actually included in the Z16 package (and were not considered "separate" options on the car) were:

- L37 396/375 hydraulic lifter engine
- M20 trans
- Special suspension
- Special 3.31 (open) axle
- Dash pad
- 160 mph speedo
- Tach
- AM-FM Multiplex (4 speaker) stereo
- Front and rear deluxe seatbelts
- Power (drum) brakes
- Power steering
- All parts of Comfort & Convenience Group "B" (inside non-glare mirror, 2-speed wipers with washer, and an outside left remote mirror)
- Trunk lamp (although there are documented examples of original cars that never had a trunk lamp)
- 7.75x14 Gold line tires
- Simulated mag hubcaps.

Z16's were Malibu SS's to begin with, so they already included bucket seats and a console, back-up lamps and a glove box lamp. However, those lamps are listed on Z16 window stickers as part of the Z16 package. Maybe whomever encoded the info to generate Z16 window stickers entered the list of items included in the Comfort & Convenience Group on a 300 or 300-Deluxe, which DID add back-up lamps and a glove box lamp. (And maybe while making that mistake they also mistakenly listed the trunk lamp too??)

So, contrary to what many people believe, not all Z16's had power windows, or simulated wood steering wheels, or vinyl tops (as can be seen in the pics above). Those items, and a limited number of other options, were available as an RPO to add to any Z16. No other options from the regular 65 Chevelle option list could be added to a Z16. The available ones were -

- Black vinyl top
- Tinted windshield, OR all tinted glass
- Bumper guards
- Power windows
- Simulated wood steering wheel
- Tilt steering column
- Spare tire lock
And maybe a trunk lamp ??

***
As to special Z16 parts, the list is long and in some cases very surprising that so many one-off parts were designed and manufactured for a run of only 201 cars. Many folks have tried to build clone Z16's, with varying success. But rarely do they realize how difficult it is to find all the parts to do one that is highly accurate. Likewise, when someone finds a real Z16 project car to buy, they are often astonished once they get it home to learn that, depending on what all is missing, they may need to spend another $50K to $80K to buy all the missing pieces, if they can even find them for sale!

Some of the special Z16 parts were -

Engine - Not an L78, but RPO L37, specific to the Z16 package. 375HP with hydraulic lifters. Other unique components were -

- Chrome valve covers and air cleaner lid carried over to 66, and the air cleaner base was shared with the 65 L78 and 66 L72 big cars. But the cross-flag emblem is die cast (not a sticker), and only appeared on the Z16.

- The intake (cast 3866963) was shared with Vette and big-car L78 engines. However, since all Z16 engines were built very early (no later than the first few days of April), most of them (and certainly all the earlier ones) used the first design intake which has a weird casting number with two digits on a raised boss (looks like there was a mistake or a number got changed, and that was a temporary fix). That disappeared from later intakes which are much more common to find.

- The carb (List 3310) was Z16-specific. Dated assembly line units are rare and expensive. 3310's were built for many years after 1965, but nothing built after September of 1965 looks one bit like an assembly line 3310. Center body, both bowls and one metering block were all unique.

- The thermostat housing is shared only with 63+ fuelie Corvettes!

- The Distributor is Z16-specific.

- The exhaust manifolds were Z16-specific. Although one casting number carried over into 66, it is not the same manifold. The Z16 manifolds have no boss for A.I.R smog tubes. These are almost priceless and almost impossible to find if you need a set.

- Timing cover is 1965 L37 and L78 only.

- Water pump pulley is Z16-specific. It was later used again only on 67 Chevelle L78's without A.I.R. smog. So this pulley only came on 794 cars from the factory!

- Alternator brackets are 1965 396 only. They are different from 66 and later brackets.

- Bell housing is the unit from the 1965 big passenger car with 409. Not 63 or 64 409's as often claimed by eBay sellers!

- Engine wiring harness is Z16 specific and uses a ballast resistor.

Radiator - Also Z16 specific. It was a hodge-podge of parts from the Harrison radiator parts bin, using some big car 409 components, some Chevelle HD radiator components, and some new parts made just for the Z16 units. This is another unobtainium part.

Heater hoses - Believe it or not, the lower heater hose used an S-shaped metal pipe insert after the first few inches of hose at the firewall, to move the hose over away from the valve cover and exhaust manifold.

Transmission - There was a Z16-specific trans part number listed in the AIM, but it is shown as cancelled before the first car would have been built. But I have an original part number tag from one. Also, the ECL book shows a quantity of 201 M20 transmissions under a separate code from the normal ones, which we are confident is the Z16 code. But there would have been no reason for a different code from a 327 M20 if they had used the same trans as the 327, as the AIM cancellation note suggests.

Drive shaft - Z16-specific.

Front brakes / suspension -

- The ball joints, and everything outboard of the ball joints, are Z16-specific parts (except the brake parts inside the drums, which are same as a full-size Chevy).

- The spindles and backing plates are Z16-specific, never used on any other vehicle.

- The front hubs are also Z16-specific, as well as the wheel studs, but those did get used again in 66.

- Front springs and the big front sway bar are Z16-specific. Later F41 cars have a similar bar, but there are easily visible differences.

Steering -

- The power steering box is Z16-specific, with a different casting number and internals. So far I have only ever found one date on a legit Z16 box, so appears all 201 may have been built the same day.

- The power steering pump and reservoir mounting bracket are Z16-specific. The pump looks a lot like a 66 Chevelle 396 pump, but they are different.

- The PS pump brackets are different on 65 396's. Again, they look a lot like a 66 396 parts, but they are different.

- The steering column is also Z16-specific, using a bolt-on lower flange (unless it is a tilt wheel car - the small block and big block tilt were the same, as both used a bolt-on flange).

Rear axle - Often mistakenly called a "shortened Impala axle", it was actually much more complicated than that. It used a Chevelle 12-bolt center pumpkin, shortened big car axle tubes with big car axle bearing housings and axle bearings, big car brakes, one-off axles just for the Z16, and one-off parking brake cables and brake lines. But it had all the standard Chevelle mounting provisions.

Rear suspension -

- Z16-specific springs

- Rear sway bar with boxed lower control arms. These parts are the same as the 64-65 442 Oldsmobile. But they are visibly different from the parts used on later Chevrolets, which are often mistakenly installed on restored Z16's since they were available as NOS parts for decades.

Wheels - The wheels are Z16-specific. You may have heard they were riveted rather than welded, but it was more than that. They have special outer rims that were necessary to allow the wheels (with standard Chevelle back spacing) to clear the large rear brake drums from the big passenger car. Many restored cars have fake wheels with fake rivets (or later riveted Impala wagon wheels), but none of those fakes have the correct Z16 outer rim.

Exhaust - The exhaust pipes and mufflers (which were welded together) were Z16-specific in 65, although used again on 66 396 Chevelles. The tailpipes are Z16-specific.

Boxed Frame - Contrary to popular belief, it is not just a regular 65 Chevelle convertible frame. There are differences, and it had its own separate part number. This is one place where restorers who replace and restamp VINs on rusty frames get caught, as they rarely know how easy it is to spot a replaced frame under a Z16!

Body mounts - The assembly instruction manual says that two additional mounts were to be used, under the rear seat. (But in many original Z16's they are not there.)

Body - Most Chevy folks know about the special rear trim, and the Malibu SS emblems relocated to the front fenders. What very few people realize is that the body shell itself is different (and no, I'm not just talking about the holes for trim). Certain parts of the cowl of a real Z16 body are different from a regular 65 Chevelle body. This little known fact has been the downfall of many rebodied Z16s, when a potential buyer asks me or another knowledgeable Z16 person to inspect a car!

***
I suspect everyone reading this already got bored awhile ago, so I will shut up now. For those who remain interested, if you have any questions, shoot them at me!

Jeff

[Too Many Projects]

Bored Jeff ??? never, I've wanted one of these since I learned of them in late '69. A friend had a Green one in about '70-71. Was it authentic and original ? Hard to say, as I remember very little for details about the car, other than it had a very hard time grabbing the pavement. He bought it to compete with our other friend who had bought a new '69 300 Deluxe with the L78/TH400 right after graduation.

A thought on the reason for the 3.31, open, rear gears may be from the last couple sentences of the memo above. Chevrolet didn't produce these to be stripped down and turned into race cars right away. They wanted them out in the publics eyes to see what they could have by ordering a new Chevelle. The same could apply to the ONLY 375hp 396 ever built with a hydraulic cam. That cam wasn't going to be the best option for high rpm, wot, drag racing either. They wanted the cars driving around, reliably, as advertisement.

[Lee Stewart]

From the GM Heritage Center:



A Vinyl Roof and Power Windows were originally supposed to be part of the Z16 package. They were made options instead



Were any of the Z16s built with Heater Delete? It was an option.

[Lee Stewart]

Originally Posted by Too Many Projects

Bored Jeff ??? never, I've wanted one of these since I learned of them in late '69. A friend had a Green one in about '70-71. Was it authentic and original ? Hard to say, as I remember very little for details about the car, other than it had a very hard time grabbing the pavement. He bought it to compete with our other friend who had bought a new '69 300 Deluxe with the L78/TH400 right after graduation.

A thought on the reason for the 3.31, open, rear gears may be from the last couple sentences of the memo above. Chevrolet didn't produce these to be stripped down and turned into race cars right away. They wanted them out in the publics eyes to see what they could have by ordering a new Chevelle. The same could apply to the ONLY 375hp 396 ever built with a hydraulic cam. That cam wasn't going to be the best option for high rpm, wot, drag racing either. They wanted the cars driving around, reliably, as advertisement.

The Z16 was available in three colors only: Tuxedo Black, Regal Red and Crosus Yellow. No Green.

[jeffschevelle]

There are two cars I know of that were repainted in green metallic relatively early in life.

One was in RI, originally a red car, and is reportedly long dead and gone. Only it's POP and some old pictures still survive.

The other car is still alive. Yellow car originally. Then red primer, then green paint. Then gray primer later. The car was in Columbus, Indiana in the late 80's. It eventually made its way to NC, and was hidden away in the underbrush just a stone's throw from my uncle's house 15 minutes from here, from about 1990 until 2020! The owner passed away in 2020, and his son contacted me to help him identify all the Z16 parts that were scattered and stashed all over his dad's property in multiple buildings, as well as outside.

He has now resurrected the car, fixed the floors, installed a new interior, and has it running and driving with a monster big block in it temporarily until the Z16 engine is rebuilt -- which I found mixed in amongst several dozen other 65-67 big blocks stored in one area on the property. (I'm glad there was no video running, so no one else will ever see me squeal like an excited school girl when I read that deck stamp!!)

He was able to scrub much of the primer and green off, revealing bits of original yellow here and there (mixed in and amongst copious amounts of surface rust). He brought the car to the Carolina Chevelle show at Hendrick Motorsports this past weekend, and it was a big hit!

I will ask him if he has gotten the NCRS shipping report yet to see where it was originally sold.

[dykstra]

Hi Jeff, Thanks for the info. Maybe i missed it, but why didn’t GM offer positraction on these Z16 Chevelles?

[Lee Stewart]

Originally Posted by dykstra

Hi Jeff, Thanks for the info. Maybe i missed it, but why didn’t GM offer positraction on these Z16 Chevelles?

Z16s did NOT get a posi. Chevrolet felt that with the rear sway bar, boxed lower control arms and the convertible frame that the rear was tuned enough to not need the "crutch" of a limited slip differential. Seems odd, but true. If you look at the photos of all the test drives in magazines back in the day, they are all laying down two smokey patches so apparently they knew what they were doing.

https://www.chevelles.com/threads/di...a-posi.336718/

[Xplantdad]

Hi Jeff,


Thanks for continuing on with all of the Z16 info amongst all of the other research that you do for everyone! I know that Dave Miner was intimately involved with Z16's up until he passed away. He was a great guy....