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Old 01-19-2019, 07:28 AM
9C1Beater 9C1Beater is offline
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Default F41 Rear Springs with 6 Leaves

Hey All...I'm posting some photos of the F41 rear suspension on my 1974 Nova COPO 9C1 police car. I have posted quite a bit of info on the car in another thread in this section, and figured some of you might like to see this car's unusual rear springs.

I took quite a few photos of the rear suspension and was investigating if it was essentially the same as a Yenko Nova when I discovered one marked discrepancy between the two suspensions...Yenko Nova rear springs have 5 rear leaves and my car has 6.

The car has 120k original miles and was ordered by a Chevrolet executive named Rick Mahoney at the Los Angeles Zone Office for use as a high-speed police car demonstrator (it was a "Brass Hat" car...see documents in my other post). He used the car for 5 1/2 months and then sold it to Los Angeles County where it was used by the LA Sheriffs Dept as an undercover car at the West Hollywood station (it still has a shotgun rack in its trunk). It sat undriven in a garage in the Hollywood Hills for 32 years until I bought it in 2017.

It has many GM stickers still on its suspension components, including a yellow sticker on the driver's side with the part number "340399". The outer brackets have partial blue and white GM paper stickers, and the right support rod has a very faded paper tag that I believe says "Special" on it. The left support rod has a splat of dark green paint visible at the very bottom (it isn't visible in any of the photos, but it's there).

In addition to its mostly Z28 suspension components (from the factory), it also has rear drums and shoes from a Chevelle station wagon.

I am curious if these are possibly big block Nova rear springs (even though the big block was no longer available by the time this car was built). The car handles with virtually no lean in very hard cornering, and it rides very firm (almost like a truck when going over freeway expansion joints...no give in the suspension).
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  #2  
Old 01-19-2019, 02:51 PM
Flying Undertaker Flying Undertaker is offline
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Default F41 Rear Springs with 6 Leaves

It's possible that these were one-off springs due to this car being a prototype as a police car. It is a Nova 4 dr. and besides having the F41 performance handling package needed for pursuit, it must also have the ability to place a couple large perps in the back seat as well. Don.
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Old 01-20-2019, 02:32 AM
9C1Beater 9C1Beater is offline
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Don, you are no doubt correct.
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Old 01-21-2019, 01:24 PM
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Wink COPO Nova Cop Car...

As a Nova fan, I am enjoying the discussion on the Nova police cars...especially the details on the equipment and upgrades that were part of the package.

Thanks for sharing

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Old 01-22-2019, 01:22 AM
Kurt S Kurt S is offline
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Why do you say it has a Z28 suspension?
I'm not super knowledgeable on 74 Novas, but it appears to have the normal F41 Nova suspension.
Can you post a picture of the complete bottom of the buildsheet?
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Old 01-22-2019, 06:02 AM
9C1Beater 9C1Beater is offline
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Kurt, I know you have done a lot of research on 1st Gen Camaros, and you realize that GM engineers borrowed heavily from the Nova parts bin to create the 1st Gen Camaro, then did the same to upgrade the 3rd Gen Nova with 2nd Gen Camaro parts. If you read all I have posted on this car and its incredible documents on Steves Nova Site under "1974 Nova 9C1 Police Car...only survivor of 17 built", you will understand the historical importance of this car. It is the 2nd Nova police car ever built and was ordered by a GM executive who was the West Coast Fleet Sales Manager at Chevrolet's Los Angeles Zone Office in Century City (he was an executive and this was a "Brass Hat" order...with a GM document that even says "Brass Hat"...and no comments on here about that document...that really surprised me).

I have shown the car to Harry Hammond, who was one of the 2 engineers tasked with turning the 4-door Nova into a useable police car...he said that involved borrowing heavily from the Z28 parts bin. Harry's co-engineer in the project was Jim Ingle, who was an assistant to Vince Piggins at the GM Tech Center in Warren, MI. All 3 of those men knew the Nova's floor pan and suspension were virtually identical to a Z28's, so that's where they looked to improve its handling and braking...they weren't re-inventing the wheel, so they used the best stuff available...Z28 stuff. They experimented for 2 months with various springs, shocks, bushings, sway bars, and wheels at the GM Proving Ground in Milford, MI to get their Nova police car to handle better than the Plymouth Satellite, Dodge Coronet, and AMC Matador that they knew it had to beat in order to get the LA Sheriffs Dept to order them. I posted a GM document earlier in this post where Jim suggested that Z28 eye bushings be used on the rear springs to control axle hop under hard acceleration (which indicates that this lowly 4-door was capable of doing burnouts...it is a muscle car). That original GM document shows that this car was borrowing from the Z28 parts bin. Another example is that Harry said it has a Z28 steering box. It also has a Z28 dual snorkel air cleaner, Z28 4-spoke steering wheel, and F41 special performance suspension...Harry said it was essentially a 4-door Z28. Another interesting thing about it is that it has 6-leaf rear springs...one more than a Yenko Nova or 2nd Gen Z28. If you would like to see the car, I plan on driving it up to Detroit this summer for the "Orphans Show" in Ypsilanti (I see you're right next door in Ann Arbor). Harry Hammond gave me many interesting GM documents relating to the development of the Nova police car, but obviously did not save everything. He is now in his early 80s and doesn't have the time, documents, or memory to recreate every facet and nuance of this car, which is an exact duplicate of the white '74 prototype Nova police car. Harry also provided a lot of documents and commentary to Ed Sanow when he was writing his excellent book, "Chevrolet Police Cars" (Harry gave me his copy of the book which contains a heartfelt thank you from Ed to Harry for all his invaluable help during the writing of the book...Harry was chief engineer for Chevrolet's various police car programs from 1974-2001 and was Ed's biggest source of information and photos for the book). If Harry says my car is "essentially a 4-door Z28", then I believe it is essentially a 4-door Z28.

I realize this is a 4-door, but it is an incredibly interesting and historical 4-door that gets virtually no interest from Chevy muscle car experts because it is a 4-door. I can post more stuff on here, but it doesn't seem like there is very much interest in it. I do know that Phil Borris and Drew Hardin (from Muscle Car Review magazine) were amazed at its untouched status, documents, and history. I realize it is not a Yenko Nova or Camaro, but it's just as cool, and just as interesting (to some). I posted photos on here of its left cylinder head which is a Z28 head, and that it has an 8-inch harmonic balancer...Phil Borris, a celebrated Chevy muscle car expert and author, saw the car and said he thinks it probably has Z28 internal components (which I will photo document when I get the engine out within the next 2-3 weeks). It has incredible suspension for a lowly 4-door and was capable of .86 Gs on a skidpad, and 1.2 Gs in braking (Harry said it had Z28 front brakes and the drum brakes from a Chevelle station wagon on the back). When I posted photos of its F41 rear suspension and the fact that it has SIX LEAF REAR SPRINGS, that generated almost no comments on here (does any other factory Nova or Camaro have such springs, even a COPO 427 Camaro or Nova???). Aside from the fact that this car is a 4-door, its other problem is that there's nothing to compare it to...there are no other 1974 Nova police cars known to exist (and if there were, they would also be lowly 4-doors that would also not generate much interest).

I posted a copy of its build sheet on SNS if you want to look at its codes...no one else has actually looked at it up to now other than the guys at the SCW building at the GM Nats who were shocked to see a 4-door was ordered with F41 suspension and E70-14 lettered tires...see portion of build sheet at the top of this post. I will post the build sheet on here for all to enjoy (and probably ignore).

You had previously mentioned that it was no big deal that it had 14x7 inch steel wheels, but I posted a GM document that showed that when the project was first being put together the engineers involved (including Dave McClellan, the engineer who was put in charge of the Corvette program in 1975...just a year later than this project) weren't yet thinking about anything other than 14x6 wheels from a Chevelle station wagon to improve its handling at the skid pad (Harry said those wheels were less prone to flexing under hard cornering than standard 14x6 wheels). The 17 '74 Nova police cars are still the ONLY 3rd Gen Novas I know of that came with plain 14x7 steel wheels (non-SS wheels)...they are coded "EM" on its build sheet. After providing you with that GM document I received no comment back from you until now, and your current comment seems to suggest yet again that this car is nothing special and that I somehow should prove its Z28 componentry (if I am misreading your intent, then please correct me...I can apologize when needed). It doesn't matter if "thousands of '70s GM cars had 14x7 inch wheels from the factory" (your words), what does matter is that AT THE TIME THIS CAR WAS BUILT, there were no other Novas being built with 14x7 plain steel wheels. It was the research on this Nova that led GM engineers to put them on other cars in later model years.

I can measure every component and write about it on here, but all I will get are more questions about its authenticity, or more disinterest because it is a 4-door and not a Yenko, so what's the point? It is an exact duplicate of a factory prototype (and I thought Chevrolet prototypes were actually something to be revered, especially on this website), and the only one known to exist (and a COPO, which I now know doesn't mean very much because it is a "4-door COPO"). I was told by a guy at the SCW tent at the Carlisle GM Nats this past June that it was possibly the best documented and historical Chevy police car in existence. My car is not only an untouched original "survivor", but has also been verified by the engineer who built it, and is backed up with a build sheet and many GM documents...I don't know what else I need to do (or can do) to prove its provenance. I haven't seen any other cars on here (or anywhere else) than have this car's level of factory documentation and historical significance (the Nova police car is considered to be Chevy's most-significant police car ever built, and one of the 10 greatest police cars of all time...and this is the 2nd one ever built...the LA Zone Office's police car demonstrator).

BTW Wilma, I have read many of your posts and enjoy your involvement with Novas. And Kurt, I greatly appreciate your obsessive research into Camaros...I would welcome any such investigation into my Nova. But please remember...it's just a 4-door!

PS...if you look in the upper left hand corner you will see that the scheduled build date for this car at the Van Nuys. Calif plant was 5-21. Harry said the order form for this car, the gold demonstrator was filled out on Friday May 3rd, 1974 while he and Jim were having dinner at GM exec Rick Mahoney's house in Northridge, CA. The order was sent to GM on Monday May 6, so if this car was actually built on May 21st, then that was only 15 days after the order was placed. Are you aware, Kurt, of any other GM car that has a faster documented build time than this car? That is yet anther example of its importance to the execs at GM.
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Last edited by 9C1Beater; 01-22-2019 at 02:46 PM.
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Old 01-22-2019, 02:37 PM
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I wouldn't be so quick to say that there is no interest in this car. All though I have not posted any comments, I have been following every post that you have put up, and this is an interesting car to me. I have never seen the 6 leaf springs on anything before and it would be interesting to know how they were built. Please keep posting here so that those of us who are interested can keep up.
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Old 01-22-2019, 03:10 PM
9C1Beater 9C1Beater is offline
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Big Gear Head, thank you for your interest. I plan to post more photos of the springs which will include their exact dimensions and the number of clips holding them together. I believe that they are one-off custom springs that GM probably put on all 17 of the '74 Nova police cars. The fact that GM went to all the trouble and expense to have them produced indicates GM management's desire to steal the cop car business away from Chrysler (which was the leading seller of law enforcement vehicles at that time). The fact that this car's springs were built at a GM plant and shipped (probably) from Detroit to the Van Nuys plant in less than 15 days (they had to be present on the assembly line right before this car showed up) is yet more evidence of this car's importance. Under hard cornering with this car there is virtually no lean. I owned a '70 Boss 302 in 1975 when I was 18, and this car is the closest thing I have ever driven to the feel of that car.

I am 100% certain that Rick Mahoney did some tricks to its engine right after he got the car. Its engine is coded "CKD" in the stamping pad (and "KD" on the build sheet), which is a standard L48 350 code, yet it has Z28 parts. I believe he had the engine built with the Z28 parts to make it more entertaining for the cops during test drives. He had a buddy at Arrow Chevrolet in Los Angeles who probably performed the work (Arrow is also where Rick liked to have his Zone Office cars delivered). This demonstrator must have made quite a favorable impression, because the LASD ordered 75 4th Gen Nova 9C1 police cars, and another 222 in '76 (I don't have ordering figures for '77 and '78 for the LASD, but Ed Sanow said that it was basically their sole squad car during those years (the Nova 9C1 was superseded by the Malibu 9C1 in '79, mainly due to the Malibu's larger rear seat area).

PS...I will post a photo on here of me at 18 with shoulder-length hair while leaning on the Boss...the car is covered with snow and has 1975 Iowa plates (driving a Boss 302 in the SNOW...blasphemy!!!). It was just another car back then, and all the young punks were cruising around the streets in muscle cars while looking for races and chicks with Aerosmith or ZZ Top cranking on the 8-track tape deck.

BTW Kurt, 6 leaf rear springs are not "normal F41 Nova suspension" components.

Last edited by 9C1Beater; 01-22-2019 at 04:44 PM.
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Old 01-22-2019, 04:08 PM
9C1Beater 9C1Beater is offline
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I will be attending the Heartland Nova Show in Davenport, Iowa in June and would welcome Ken Schoenthaler's opinion of the car. I hear he has 2 Yenko Novas and is quite knowledgeable on 3rd Gen Novas.
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Old 01-22-2019, 09:40 PM
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This is an interesting car, full of unique parts and stories with lots of positive feedback. The only person who seems to continually downgrade this car is you! There is no need for an inferiority complex just because it's a '74, or a Nova, or crew cab.... It's cool, we like it.

I'll post the same response that I did on Steve's Nova site about the rear sway bar:

"Interesting setup, especially the rear spring pockets being deep enough to hold 6 leafs - and it still includes the spring pads on the top & bottom. Also, I noticed that the lower spring plates appear to be the mono spring design, and don't have the sway bar extension - which means that the bar itself is likely a little wider than the '70-'72 version. We pulled a rear sway bar out of a '76'ish 9C1 Nova about 20+ years ago, it was the correct width for a '70-'72. So, this setup is really cool...

I've had NOS rear bar setups, and confirm the green and blue paint treatment...."
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