Duntov's 1968 L-88 test cars

[Joe L.]

Re: Duntov's 1968 L-88 test cars

Joe, Thanks again for the reply.As this car has no evidence of smog or pcv systems, I was hoping there might be some tapping or bracket that could indicate that it originally had these systems.I do know they have been off the engine since before March 1970 (when 2nd owner aquired the car with less than 2000 miles) Do you or does anyone else know if the 69 (68?) test car in the car life article had the smog systems intact? I can't tell from the pictures in the article if it's present.Wouldn't removing the pvc and smog systems have voided the warrranty?

Thomas------


The ZL-1 in the Car Life article from 1969 did not have an installed AIR system. A underhood picture clearly shows that. However, as we've discussed, this was certainly not a PRODUCTION-type car. This car was undoubtedly an "engineering test vehicle" and could be expected to have many modifications which no PRODUCTION vehicle would have had. So, this car does not provide any reliable insight as to PRODUCTION configuration. As far as warranty was concerned for this particular car, it probably had the best warranty that GM ever issued-----if ANYTHING went wrong with the car for ANY reason GM would fix it. That's because it was their car and was never destined to be anyone else's car. I feel pretty confident it was destroyed after it was no longer needed.

In general, if the AIR or PCV systems were removed from a PRODUCTION vehicle by the owner of said vehicle, that would void the engine warranty. However, it would not necessarily void any other part of the new vehicle warranty.

There were certain components that might provide "telltale" information that an engine was originally equipped with AIR. However, those components could easily be removed or changed.

[Steven B.]

Re: Duntov's 1968 L-88 test cars

Thomas, back in the day when I worked in the brake and clutch mfg. business a trip to Milford included speaking with some test engineers. In addition to talking about fade properties of cashew oil based linings I asked some questions about Corvettes---fishing for racing parts for mine. We talked about, and I saw, the pontoon fendered BB Corvette and I was told Engineering got cars assembled on the line in St. Louis and then modified them as they needed - many times. They built what they wanted from production cars sometimes with parts from outside vendors and sometimes with internally designed parts.

Steve

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Steve and Joe

Thanks again for the information. What I was questioning was why a car that had such low mileage and had only been out of warranty (12 mo./12,000 mi.?) about 6 months when it was aquired would have had it's emissions stripped. My recollections of friends fortunate enough to have new cars in those early days of emissions was that normally all they did was remove the belt from the air pump.Some would go a step farther and cap the pvc carb port and go to a breather in the valve cover,but all would restore things to OEM before they took the car in for warrranty- covered service.New question... When aquired in 1970, this car was equiped wih headers and sidepipes. The owner believed them to be the Kustom headers and pipes available through G.M. Were there any other over-the-counter sidepipes available from G.M? Do you believe the sidepipes on the test car are the Kustom pipes? Other than the part numbers,are there any other indentification marks on the Kustom pipes?

[Terry M.]

Re: Duntov's 1968 L-88 test cars

Steve and Joe

Thanks again for the information. What I was questioning was why a car that had such low mileage and had only been out of warranty (12 mo./12,000 mi.?) about 6 months when it was aquired would have had it's emissions stripped. My recollections of friends fortunate enough to have new cars in those early days of emissions was that normally all they did was remove the belt from the air pump.Some would go a step farther and cap the pvc carb port and go to a breather in the valve cover,but all would restore things to OEM before they took the car in for warrranty- covered service.New question... When aquired in 1970, this car was equiped wih headers and sidepipes. The owner believed them to be the Kustom headers and pipes available through G.M. Were there any other over-the-counter sidepipes available from G.M? Do you believe the sidepipes on the test car are the Kustom pipes? Other than the part numbers,are there any other indentification marks on the Kustom pipes?

Tom,
I'm not sure your friends represented the entire range of anti-pollution fervor in the late '60s early '70s. My friends removed ALL of the AIR equipment and replaced the restrictive stock exhaust manifolds with headers. And many did so immediately on taking delivery. There were ways around the factory warranty police, so none of us worried about that.

There has been someone in the past who posted photos of the GM headers and side pipes in the past, but I don't remember who.

[Steven B.]

Re: Duntov's 1968 L-88 test cars

Thomas, the Kustom mfg'd pipes were available over the counter from GM as called out in the 2nd Ed. Chevrolet Power Book. Hefner Chev. in Fort Wayne, IN had a set in Parts Dept. I saw back in the day.

396-427 Header Assm PN: 3960709 LH, 710 RH
396-427 Collector and Side Mount PN: 3960713 LH, 714 RH
Also available were gaskets, bolts and mufflers for the side mounts and like parts for 350 c.i.

Most guys chose the other sources/mfgs. for their headers and pipes likely due to advertising and price, and chrome.

As far as the emissions equip goes I pulled the pump, brackets, , cat., mufflers, etc. at less than 100 miles past 12,000. I had all parts in hand waiting for the 12,000 mark. Everyone I knew pulled everything from theiir cars (a Z-28, a 375 HP Camaro, a 396 Chevelle, a 435HP Corvette, etc.)

Steve

[Dick W.]

Re: Duntov's 1968 L-88 test cars

Thomas, the Kustom mfg'd pipes were available over the counter from GM as called out in the 2nd Ed. Chevrolet Power Book. Hefner Chev. in Fort Wayne, IN had a set in Parts Dept. I saw back in the day.

396-427 Header Assm PN: 3960709 LH, 710 RH
396-427 Collector and Side Mount PN: 3960713 LH, 714 RH
Also available were gaskets, bolts and mufflers for the side mounts and like parts for 350 c.i.

Most guys chose the other sources/mfgs. for their headers and pipes likely due to advertising and price, and chrome.

As far as the emissions equip goes I pulled the pump, brackets, , cat., mufflers, etc. at less than 100 miles past 12,000. I had all parts in hand waiting for the 12,000 mark. Everyone I knew pulled everything from theiir cars (a Z-28, a 375 HP Camaro, a 396 Chevelle, a 435HP Corvette, etc.)

Steve

To add to what Steve posted above, the header flange on the GM Kustom headers had the part number stamped on them. Same header bought from Kustom had no numbers. Another thing that was unique to the Kustom headers with side pipes was the side pipe support brackets. Where everyone else used a piece of flat metal to make the bracket, custom used a fabricated "u" channel. The side flange were turned up 1/8"-3/16".

[Steven B.]

Re: Duntov's 1968 L-88 test cars

Dick, I just noticed the style of the '68 on headers in the pic are not flat on the bottom of the tubes, and the tubes are longer, like the earlier ('67) headers. They are more like the Hooker style.

Steve

.

[Joe L.]

Re: Duntov's 1968 L-88 test cars

Thomas------


One other thing that we have not discussed here as of yet: what is the engine suffix code of the engine in this car? If it's "LV", "LO", or "MR", then that engine was originally built at Tonawanda with an AIR pump bracket AND with exhaust manifolds with AIR fittings. So, if those are not on the car now, they were removed at some point. The only possible way that the car could have been originally delivered without these components would be if they were removed at St. Louis or if the car had been shipped to Warren and removed there. In the latter case, the car would have been some sort of "engineering test vehicle" that was later sold to the public in its modified form. I VERY much doubt this occurred, especially through normal dealer sales channels as this car was apparently sold.

I realize that the car has headers on it now, so that "takes away" the ability to determine the originally installed manifolds. I really doubt that any cars sold through normal dealer channels, L-88 or otherwise, were ever originally delivered to the dealers with headers installed. They may have been delivered to the customers with headers installed, though.

As far as PCV goes, if the car is not equipped with that, what sort of crankcase ventilation does it have? Does it have a road draft tube and ventilator cap installed in the valve cover PCV orifices like 1967 L-88? It must have some form of crankcase ventilation and big blocks were never designed with in-block provisions for road draft style crankcase ventilation. All big block valve covers ever used on a PRODUCTION engine were designed for PCV (but for 1967 L-88 were alternately used for the road draft type crankcase ventilation).

If the car has some previously unknown engine suffix code, then original engine configurations lacking AIR provisions would be POSSIBLE. Not likely, but POSSIBLE. But, if it has one of the known codes, then the engine left Tonawanda with provisions for AIR and PCV.

[Dick W.]

Re: Duntov's 1968 L-88 test cars

Dick, I just noticed the style of the '68 on headers in the pic are not flat on the bottom of the tubes, and the tubes are longer, like the earlier ('67) headers. They are more like the Hooker style.

Steve

.

The flatten'd headers were made by Bill Thomas??. All the Kustoms I have seen or owned have been the convential round collectors. It is possible that the side pipes may have been slightly longer than Hookers. When you see Hookers and Kustom headers side by side, you see a very obvious difference. In the early years of production of the Kustoms, I bought at least 4, if not five, sets new, one of them coming from Chevrolet, the rest direct from Kustom. The set we installed on a '67 were from GM and had the numbers stamped on the flange. They still exist, though not on a car today.

NOS Kustoms are very difficult to find. Carlisle many moons ago, Doc McCagh found me a NOS set of the sidepipes still in the boxes. I though I was going to break my neck getting to the vendors spot. I paid a grand sum of $125 for the pipes..

Just noticed that they had a heat shield over the pipes on the pictured car. I found out right quick that polyester pants and side pipes did not go together. Still bear a mark on the calf of one leg

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Terry,Steve,Dick,and Joe,

Once again your replies are most appreciated. First, the numbers off the headers that the 2nd owner gave me are 3960710 and 3960708. He maybe misread the last digit of the 3960709.What he told me also was that the sidepipes were shorter in length than the Hookers he replaced them with. He felt that the shorter length made the exhaust less tolerable on long cruises. Of course, the fact that he had no muffler inserts could have contributed . I also think that he prefered chrome to the white paint on the Kustoms.Were the Kustom sidepipes available in different lengths? Now, about the engine. When he purchased it, engine had conventional breather caps. However, behind the seats, was a "flattened-out like a pancake" (his description) contraption that he, unfortunately, thought was some home-made device. It was only many years later that he learned about the 67 road draft tubes and realized that was what he had . He stated that the damaged tube he had differed from the road draft tube he saw a picture of in that on the end of his tube it had some kind of vented cannister.Also, in similar flattened condition,was the original air cleaner base.This base had no flame arrestor.When he ordered a new air cleaner assembly from G.M, it came in with the arrestor. Engine code is TO119IT .Intake is 3933198. Is the raised pad on the intake the only place where the date would be found? Expansion tank and radiator are both A-68. The peculiar thing is that the trim tag build date looks to be c11(????).

[Joe L.]

Re: Duntov's 1968 L-88 test cars

Terry,Steve,Dick,and Joe,

Once again your replies are most appreciated. First, the numbers off the headers that the 2nd owner gave me are 3960710 and 3960708. He maybe misread the last digit of the 3960709.What he told me also was that the sidepipes were shorter in length than the Hookers he replaced them with. He felt that the shorter length made the exhaust less tolerable on long cruises. Of course, the fact that he had no muffler inserts could have contributed . I also think that he prefered chrome to the white paint on the Kustoms.Were the Kustom sidepipes available in different lengths? Now, about the engine. When he purchased it, engine had conventional breather caps. However, behind the seats, was a "flattened-out like a pancake" (his description) contraption that he, unfortunately, thought was some home-made device. It was only many years later that he learned about the 67 road draft tubes and realized that was what he had . He stated that the damaged tube he had differed from the road draft tube he saw a picture of in that on the end of his tube it had some kind of vented cannister.Also, in similar flattened condition,was the original air cleaner base.This base had no flame arrestor.When he ordered a new air cleaner assembly from G.M, it came in with the arrestor. Engine code is TO119IT .Intake is 3933198. Is the raised pad on the intake the only place where the date would be found? Expansion tank and radiator are both A-68. The peculiar thing is that the trim tag build date looks to be c11(????).

Thomas-------


I mistakenly provided the 1969 L-88 engine codes in my last post. Since this car is a 1968, those do not apply. For 1968, the only L-88 engine code of record is the "IT" code. I am very confident that this engine left the Tonawanda engine plant with provisions for AIR (i.e. AIR pump bracket and AIR fitted manifolds). Whether and where those provisions were subsequently removed is the question. I do not think that GM would have delivered a car to a dealer for retail sale that was not equipped with AIR. For 1968, federal regulations required that ALL cars have exhaust emissions control and I don't think that GM would have delivered a car that did not comply. AIR was the only system available for exhaust emissions control on a 1968 L-88. Theoretically, a dealer could have removed it for a car that was not to be registered for on-road operation and some might even have been willing to do it for a street car. But, I don't think that GM would have done it FOR A CAR SOLD THROUGH NORMAL DEALER CHANNELS.

If the trim tag says "C11" that would mean a body build date of October 11, 1967. This would not really work for a radiator and surge tank manufactured in January, 1968 (A 68). Something strange must have happened with this car assuming that radiator and surge tank are actually original to the car.

Also, manifold casting dates on these manifolds are usually on the UNDERSIDE of the manifold.

[Terry M.]

Re: Duntov's 1968 L-88 test cars

A "C" on the trim tag can easily be a G. Even experienced judges make that mistake. The VIN will tell the real tale. G = February, which would make all the other dates you mentioned workable -- except for one thing. In 1968 February 11 was a Sunday. If the trim tag has a Sunday date it will be the first I have seen in over 30 years of looking at them.

[Steven B.]

Re: Duntov's 1968 L-88 test cars

The flatten'd headers were made by Bill Thomas??. All the Kustoms I have seen or owned have been the convential round collectors. It is possible that the side pipes may have been slightly longer than Hookers. When you see Hookers and Kustom headers side by side, you see a very obvious difference. In the early years of production of the Kustoms, I bought at least 4, if not five, sets new, one of them coming from Chevrolet, the rest direct from Kustom. The set we installed on a '67 were from GM and had the numbers stamped on the flange. They still exist, though not on a car today.

NOS Kustoms are very difficult to find. Carlisle many moons ago, Doc McCagh found me a NOS set of the sidepipes still in the boxes. I though I was going to break my neck getting to the vendors spot. I paid a grand sum of $125 for the pipes..


Just noticed that they had a heat shield over the pipes on the pictured car. I found out right quick that polyester pants and side pipes did not go together. Still bear a mark on the calf of one leg

Dick, who was it that had a set of sidemounts and fender flares displayed with their car at Bloomington in the 80's? As I recall Reinhardt's Z06 was to the left/ ahead as you entered the auditiorium and this car was to the far right in the corner down by the stage. It may have been the year the Stingray and SS were displayed on stage.

Thanks,

Steve

[Dick W.]

Re: Duntov's 1968 L-88 test cars

Dick, who was it that had a set of sidemounts and fender flares displayed with their car at Bloomington in the 80's? As I recall Reinhardt's Z06 was to the left/ ahead as you entered the auditiorium and this car was to the far right in the corner down by the stage. It may have been the year the Stingray and SS were displayed on stage.

Thanks,

Steve

Steve, Stevie Wonder could see that I do not have a clue. I do not even remember that. My first BG was '85

[Clem Z.]

Re: Duntov's 1968 L-88 test cars

Thomas, the Kustom mfg'd pipes were available over the counter from GM as called out in the 2nd Ed. Chevrolet Power Book. Hefner Chev. in Fort Wayne, IN had a set in Parts Dept. I saw back in the day.

396-427 Header Assm PN: 3960709 LH, 710 RH
396-427 Collector and Side Mount PN: 3960713 LH, 714 RH
Also available were gaskets, bolts and mufflers for the side mounts and like parts for 350 c.i.

Most guys chose the other sources/mfgs. for their headers and pipes likely due to advertising and price, and chrome.

As far as the emissions equip goes I pulled the pump, brackets, , cat., mufflers, etc. at less than 100 miles past 12,000. I had all parts in hand waiting for the 12,000 mark. Everyone I knew pulled everything from theiir cars (a Z-28, a 375 HP Camaro, a 396 Chevelle, a 435HP Corvette, etc.)

Steve

why did you wait so long as i did the engine over in my new 68 Z-28 with less than 8 miles on the speedo. the mileage was from the dealer to my place. back in the day the dealers if they like you covered plenty of modified cars as i know personally. i blew up my new 1953 engine after putting on dual carbs,split exhaust manifold,duel points and a cam. the dealer not only covered the replacement but installed a 261 truck block at my request. things were different back in the days. we bought new 55 chevys raced them at darlington and brought them back and sold them as used cars thru the dealer. my dealer sold my souped up 53 chevy to some guy in his 60s and he loved because it was faster than his BIL ford.