The most "significant" Chevrolet performance car.

[Canada George]

Verne,

As I said previously, I challenge, with respect your statement that, “(No) L88s… were offered with an overall package of race-only features as was the Z-11” and that, “there was never another Chevrolet produced with so many specific packaged features for one purpose”.

Well, before we compare packages to see whose is bigger let me add the disclaimer that I do not profess to be the definitive expert on this subject. For many reasons I will attempt to explain, the subject of the L88 PACKAGE remains convoluted and open to much misconception. Hopefully my longtime interest and consideration of the matter will prevent me from adding to the confusion.

To begin with there has always been a cloud of mystery over the entire L88 program, starting from the upper echelons of General Motors themselves. This was a tricky proposition for GM; forced to make a bona fide racer available for particular eligibility requirements in the professional racing circuits. Made technically available but not marketed aggressively; in reality, heavily discouraged. A result of this is very little of a paper trail showing clearly what the L88 was all about.

But let me assure you, the L88/ZL1 Corvette was top-to-bottom, front-to-back all-out RACE CAR. The car delivered to the county’s top race teams was the very same “packaged” version available to all.

Did the package have a name? Well, not officially during the time of its production. That wouldn’t happen until ZR1/ZR2 package was released. But it was essentially this SAME package, without the L88’s special induction hood and the full race 427; these goodies were specific to the L88 alone. By the way, when I use the term L88 it also INCLUDES the ZL1. Every ZL1 Corvette is an L88 as well; the L88 order ensured you of the accompanying racing package, the ZL1 is the aluminum engine case only. If you’ve ever seen ZL1 documentation (tank sheet, etc.) this point is clear.

The package was ordered not by a designation code but by simply ordering the RPO-L88 itself. You could walk into a parts department and buy the engine alone but you could not have the factory install it on any other car but the RPO-L88. Ordering RPO-L88 meant that you were required to take a full list of other RPOs and special items. The choice was not yours; Chevrolet would not sell you anything other than the full-race configuration car. It also meant there was a list of things that couldn’t be ordered. Check the box for a radio and your order would be discarded, literally. Want a fan shroud to help keep the engine temperature tolerable? Forget it, the car was meant for the track and the track only. If money was no object and you thought power steering would be nice… dream on; this beast was anything but nice. One basic version, few allowable variances… take it or leave it. And you might not get it even if you towed the line. It was rarely easy; it required patience and persistence.

In evaluating the “completeness” of the package I give little weight to whether or not the individual elements are made available elsewhere. It is not contingent on how exclusive the individual components are. Nor do I give credence to the fact that how it is broken down for clarity or pricing purposes dictates its completeness (let alone its actuality). Tallying individual specifics, especially on different models from different time periods runs the risk of the apples and oranges analogy.

You tell me the Z11 substituted many aluminum body parts for the Impala’s metal parts; I counter that the Corvette is an all-fiberglass –bodied car, designed specifically for its lightweight characteristics. Tell me that the Z11 came with wheels that were .5” wider than what was available on a standard Impala, a positive attribute for adding a bigger racing tire, granted. I counter that the L88 Corvette came with an even wider rim; no points should be lost because other Corvettes could be had with these wheels. The point is that the equipment that was supplied with EVERY L88 order was what Chevrolet thought was necessary for racing (and racing only).

It was the technical developments of the L88 program that dictated the overall refinements of America’ only sports car. The purpose of Corvette engineering was to reach the highest level of both style and performance. The Corvette wasn’t plucked from the economy level of the Chevrolet lineup and modified for occasional forays into off-road endeavors. The Vette was all about performance… going fast, taking corners and quickly stopping. So an argument can be made that every mechanical change the Corvette underwent was in order to upgrade its overall performance, even as far as its body style design. The styling change from the midyear cars to the C3s was as much for aerodynamic purposes as it was for aesthetic appeal. Talk about development with performance in mind!

Example: since the advent of fuel injection in 1957 every high performance engine in the Chevrolet lineup with the exception of the “W” 409 was for the most part a result of Corvette-based technologies; the top power-plants that wound up in the Impala/Chevelle/Camaro/Nova engine compartments were generally supplanted Corvette motors.

You would be hard-pressed to contend that the Z11 was in any way the pinnacle performance achievement of Chevrolet history. I wouldn’t make that claim about L88/ZL1. Time doesn’t stand still; it never has. Modern innovations, especially in the Corvette arena obviously surpass those from 40 years ago; the latest model Corvette or Camaro is just as eligible as someone’s choice as most significant and in that regard there’s merit in the claim that a new Z06 is inherently an all-around better performing car than anything from the ‘60s. Improvements have not always been linear with time; there have been peaks and valleys. One of those peaks for Chevrolet was 1969-1970. We all know the story: factors of environmental concerns, oil supplies, safety and insurance issues, etc. saw the sudden end of the “performance years” and a steady decline in horsepower ratings. True performance has since returned!

The Z11 is for me one of the hallmarks of Chevrolet performance history; definitely something on my “wish list” too. On a personal level, no car is more significant to me than my 1960 Chev Biscayne drag car, mine since I was too young to drive. I’d hardly expect it to receive another vote in this poll; that’s why I chose to instead cast a ballot for what I consider to be the most significant “performer” of the muscle years. L88/ZL1 Corvette was the apex of Chevrolet performance (made available to the public) during this time and for many years following.

I have been in discussion with the top levels of the NCRS, the Corvette Museum and General Motors about finally lifting this veil of mystery with respect to the package aspect of the L88. The NCRS judging manuals acknowledge this package aspect as do all leading experts in the L88 field. Much more needs to be done to get the word out to the general public, IMHO.

So Verne, I’m quite confident you will be able to see the L88/ZL1 Corvette was the whole package; this was the car that was culmination of Chevrolet’s racing involvement and evolvement. Nothing was held back; why would it have been? Each L88 was complete and race-ready as delivered from the factory; simply bolt on the available race exhaust system and your tires of choice and you’re ready to go, and go fast. The L88s were world-beaters, capable of speeds as high as 200MPH with the right axle ratio. And durable… you don’t win the 24 Hour Endurance Race at Le Mans or 12 Hours at Sebring in anything other than the epitome of performance excellence.

Conclusion: the RPO-Z11 and RPO-L88/ZL1… both FULL RACE-ENGINED and race packaged cars. Both extremely significant!

And with that said, here is the listing of the (’68-’69) L88 RACE PACKAGE:

MANDATORILY REQUIRED OR UNAVAILABLE OPTIONS/ITEMS:

(*) L88 only
• L88 Special 427 “blueprinted” engine (FULL RACE) *
• F41 Heavy-duty suspension
• G81 Posi-traction
• K66 T.I. Ignition
• M22 Heavy-duty 4-speed *
• J50 Power brakes (vacuum)
• J56 Racing brake system *
• Aluminum H.D. radiator *
• Dual-plate clutch *
• Special ducted fresh air hood *
• Rear end gear ratios from 2.73 to 4.56 *
• Fuel octane warning label (race gas only) *
• Optional ZL1 aluminum cylinder block and 8 sleeves *
• NO Radio
• NO fan shroud (w/4-speed)
• NO Power steering
• NO power windows
• NO Air conditioning

P.S. Come see for yourself this June 26-29, 2008

BLOOMINGTON GOLD L88 INVASION (hold on to your hats!)

[camarojoe]

Great post! I will admit, i never knew too much about L88 Corvettes but after reading all that i feel like an expert.

[LS6 RAT]

Your not correct on the dual plate clutch. The L-88 used a special 12.5 inch light weight flywheel and single 11 inch clutch disc.

[Canada George]

Rat,

My sources indicate that every 2nd design L88 and ZL1 Corvette came with the dual plate clutch. The information I was passing along was slightly condensed to give some general facts; not all info is entirely accurate for every incarnation of the car in its 3 year run.

As I said, I'm NOT the definitive authority; I just thought the package aspect was worth sharing.

[PhilS]

I'd say the L-88 is more fun to cruise at 150 mph. A set of 3.08s help of course.

[LS6 RAT]

L88vetteron,

The L-88/ZL-1's used a special clutch assembly with these part #'s flywheel 3866735, pressure plate assy 3886066 & clutch disc 3886059. Which is a single plate 10.4 inch, not the 11 inch I stated incorrectly above.

The MA-6 HD dual plate clutch design used two different set-ups one for 427 usage with L-71/L89 and one for 454 usage. '69 application was flywheel 3955151, pressure plate assy 3959175 & clutch discs 3959176.
'71 454 application was flywheel 3992094, pressure plate assy 3993814 & clutch discs 3993815.
There also was a special pressure plate for these dual plate clutches 3955148, this was a unique floater plate used with both dual plate clutch applications, 427 & 454. The flywheel differences are due to 427's being internally balanced and 454's being externally balanced. The clutch discs are also different due to the '69 discs using 10 spline thread and '71's using 26 spline thread.

[Verne_Frantz]

Ray,

Excellent post. I appreciate the time you put into it. Permit me to continue our discussion by addressing a few of your points.

You stated, “In evaluating the “completeness” of the package I give little weight to whether or not the individual elements are made available elsewhere.”

Also, “You tell me the Z11 substituted many aluminum body parts for the Impala’s metal parts; I counter that the Corvette is an all-fiberglass –bodied car, designed specifically for its lightweight characteristics. Tell me that the Z11 came with wheels that were .5” wider than what was available on a standard Impala, a positive attribute for adding a bigger racing tire, granted. I counter that the L88 Corvette came with an even wider rim; no points should be lost because other Corvettes could be had with these wheels. The point is that the equipment that was supplied with EVERY L88 order was what Chevrolet thought was necessary for racing (and racing only).”

These points are very true in the context that the L-88 Corvette was an end result of years of refining the car to be more race-ready. Since many of the components of the L-88 “package” were already designed and offered with other engines, the L-88 did not have to be designed from scratch with that new equipment in order to achieve the all-out race car that it was. My point has been that the Z-11 “package” was designed from scratch, all at one point in time, for the specific outcome of producing a race car. Chevrolet didn’t have to design lighter body panels or wider wheels for the Corvette, but they did decide to do that in order to make the Z-11 meet its design intention. I don’t know of Chevrolet ever putting that much effort into another specific-purpose car with so many unique parts.

“You would be hard-pressed to contend that the Z11 was in any way the pinnacle performance achievement of Chevrolet history.”

I would never try to argue that point about the Z-11. It was just what it was at that point in time. It was just the pinnacle of “W” power.

“I chose to instead cast a ballot for what I consider to be the most significant “performer” of the muscle years.”

There is no doubt in my mind that the L-88 is the stronger “performer” of the two. I think our positions are perfect examples of the fact (as stated earlier) that everyone’s definition of “significant” is based on different criteria. I agree with your conclusion, “the RPO-Z11 and RPO-L88/ZL1… both FULL RACE-ENGINED and race packaged cars. Both extremely significant!” 100%

I actually believe that Chevy’s engineers made some mistakes on the Z-11, and didn’t go as far as they could/should have, but that’s another story.

Verne

[1967Z28]

[ QUOTE ]
I actually believe that Chevy’s engineers made some mistakes on the Z-11, and didn’t go as far as they could/should have, but that’s another story.

Verne

[/ QUOTE ]


Verne,

I'd be very interested to hear your thoughts on how the Z11 might have been improved or further developed. Also, wasn't the total built actually 57 rather than 50?

Excellent arguments for both cars from both you and Ray. I don't see that anybody is wrong. It is too subjective to ever come up with a definitive answer.

-Jon

[Verne_Frantz]

Jon,

I guess this thread has strayed a bit, but then there haven't been any new votes for the most "significant" in a while, so I guess it's ok (right Charley? )

Regarding the 50 or 57 number, I know there have been MANY quotes by magazine writers, etc stating 57 was the number. Several people who have been digging into the history of those cars for many years believe the number is really 50. A production report issued by the Tonawanda engine plant (dated I believe July '63) lists production of total engine assemblies at 50. It lists other partial engines that were shipped, but only 50 complete units. I don't believe the Flint plant would have built a car from a partial engine plus the extra parts. They were not in the engine assembly business.

Now as to short-comings, I don't see any with the engines themselves. Raising the ports on the heads and using a 2-piece intake manifold was an engineering leap for that W design in '63. Along with pushrod guides and an aluminum water pump (which I forgot to add to the earlier list ), they made more milestones with that engine (surpassing any other Chevy design of the time).

The short-comings I see are subjective. I don't see that they did anything "wrong", but I feel they stopped short. It's as though all the engineers on the project wern't on the same page, all working toward the same goal.
For instance, they took the time to replace 2 grille brackets, that weighed a few ounces, with aluminum ones. They replaced a battery tray that weighs about 2 lbs with an aluminum one. But then they also designed an all-new air cleaner the size of a washing machine and built it in steel! They did not move to an aluminum radiator. I think more items could have been made of aluminum, but then, they might have learned an expensive lesson when they ruined a set of inner fender dies making the aluminum ones for '62.
The weakest point of a '63 passenger car was the rear axle assembly. Most other serious drag racers had already added a left upper rear control arm to control housing twist, but (again, contrary to rumor) they were not provided on the Z-11 Impalas.
A heater delete option was not part of the RPO Z-11 package. Someone just simply forgot......or thought they were also building a race car that could be driven to the store in the winter. It was up to the buyer to realize a heater was standard equipment on a '63 Impala, thus he should specify the delete option. There are several known Z-11s that were delivered with heaters.
And of course, they did not go to the extent that Ford or Mopar did with light doors, teeny seats or a trunk mounted battery.

All those subjective short-comings aside, I still believe the RPO Z-11 was Chevy's most serious attempt at building a complete race car bundled in one RPO, available to the public (although few), with such an assortment of unique equipment not available on other models.

Verne :beers

[x Baldwin Motion]

Excellent info from both Verne and Ray! I will be going to the first cruisenight that I've been able to take my car in about three years!! Maybe a few Z11 and L88 owners will be there conversing on the significance of their vehicles and I'll chime in !!

Thanks Guys