GM Experimental Prototype SBC 3x2 / Tripower setup

[1969HO455]

Looking for info on this setup. I have heard there were only a few of these experimental prototypes built, GM Winter's casting stamp, SBC 3x2 (Tripower) setup. Holley carbs similar to the BBC Corvettes. I've heard they were tested for Trans Am racing, and Smokey Yunick had some experience with these. Thanks for any info you guys can share.

http://www.yenko.net/ubbthreads/pics/usergals/2016/04/full-13757-42524-gm_sbc_3x2_setup_1.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2016/04/full-13757-42525-gm_sbc_3x2_setup_2.jpg

[William]

That was to be the L70 350 option for 1967; it's shown in the 1967 Assembly Manual. Cancelled April 1966. A few '0-' manifolds are known to exist.

If Smokey Yunick had anything to do with it he didn't mention it in his book. Since Chevrolet cancelled it long before introduction day I doubt it was ever considered for the Trans-Am. It is not listed in the SCCA Homologation papers for the Z/28.

[novadude]

Is that for real? I never even knew GM was considering such a thing for the SBC, let alone for a '67 350.

[70 copo]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 1969HO455</div><div class="ubbcode-body">Looking for info on this setup. I have heard there were only a few of these experimental prototypes built, GM Winter's casting stamp, SBC 3x2 (Tripower) setup. Holley carbs similar to the BBC Corvettes. I've heard they were tested for Trans Am racing, and Smokey Yunick had some experience with these. Thanks for any info you guys can share.

http://www.yenko.net/ubbthreads/pics/usergals/2016/04/full-13757-42524-gm_sbc_3x2_setup_1.jpg
http://www.yenko.net/ubbthreads/pics/usergals/2016/04/full-13757-42525-gm_sbc_3x2_setup_2.jpg
</div></div>

The on the spot recollection from Norwood was that prototypes of the L-70/Camaro were made-and striped in paint just like the Z/28 was later in production. Your assertion about a potential connection to Trans-Am at the planning level is accurate from what my research has discovered.

[Hawkeye]

What is the history on the pictured car? Do you have any additional photos?

Thanks for sharing.

Marty

[68l30]

I have come across &quot;A&quot; Winters marked SBC 3X2 manifold before. I was intriqued by the markings and the seller wanted a ridiculus amount of money, at the time. Was it a GM piece? Who knows, Winters is close enough to us in NEO, lots of cool stuff and stories pop up.

BIG

[elcamino72]

Very interested to know more about this car. A few of these were supposedly built in Norwood for testing ... did one survive? I suppose the suffix code on the engine would be helpful as would the VIN and cowl tag data of the subject car.

[Lynn]

If one survived, it likely gave up its rare parts to this car. The car pictured is a 69, as is the engine, and the hood.

[Kurt S]

Trans-Am with a non-eligible displacement engine??

[novadude]

Is that a 'modern' K$N filter element on that crusty old engine? Fake Patina?

[68moz28rs]

Doesn't look like there's even a third carburetor? Correct me if I'm wrong but if you look at the farthest carb and look at the distance between that and the distributor, It doesn't look like there's nearly enough room. Also I don't see the third line on the distribution block for the fuel. Could this just be a 2x2 intake?

[PxTx]

Would love to see more. I even dig the old MSD box. Any chance there are more pics?

[old5.0]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: novadude</div><div class="ubbcode-body">Is that a 'modern' K$N filter element on that crusty old engine? Fake Patina? </div></div>

K&amp;N's been making those cotton filters since the 60's. I wouldn't take an old K&amp;N as evidence of fakery.

[JoeC]

Do you know what the numbers and date codes on the carbs are?

[dboles]

What's with the modern braided fuel lines and fittings. This doesn't add up.

[PxTx]

I agree these don't have that traditional look I'm familiar with, but when do you think these were 1st used in automotive applications?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dboles</div><div class="ubbcode-body">What's with the modern braided fuel lines and fittings. This doesn't add up. </div></div>

[old5.0]

Could be 80's stuff, but, hey, it's 2016. A car modded in the mid-80s, abused for a few years and parked for the next 25 would have plenty of legitimately earned patina.

[earntaz]

As a retired aircraft maintainer, I can tell you stainless steel-braided hose and red/blue aluminum fittings were used on AF jets I worked on back in the early '60s. So I am sure they were used for &quot;exotic&quot; applications such as this 3X2 setup. TAZ <<GRAEMLIN_URL>>/flag.gif

[Mr. Chevy]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 68l30</div><div class="ubbcode-body">I have come across &quot;A&quot; Winters marked SBC 3X2 manifold before. I was intriqued by the markings and the seller wanted a ridiculus amount of money, at the time. Was it a GM piece? Who knows, Winters is close enough to us in NEO, lots of cool stuff and stories pop up.

BIG </div></div>

A fella I knew in Canton, Ohio told me that more Winters aluminum intake manifolds &quot;went over the fence&quot; and were stolen than actually put on cars back in the day. He stated there were lots of intakes floating around the Canton area and most likely still are stuffed away in garages.

Rich

[70 copo]

Here is the prototype Air Cleaner decal image... Enjoy! <<GRAEMLIN_URL>>/biggthumpup.gif What could have been and was not....

(Cross Flags)
<span style="font-weight: bold">TURBOFIRE 350</span>

<span style="font-weight: bold">3 X 2</span>

<span style="font-weight: bold">360 HORSEPOWER</span>

[Lynn]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: earntaz</div><div class="ubbcode-body">As a retired aircraft maintainer, I can tell you stainless steel-braided hose and red/blue aluminum fittings were used on AF jets I worked on back in the early '60s. So I am sure they were used for &quot;exotic&quot; applications such as this 3X2 setup. TAZ <<GRAEMLIN_URL>>/flag.gif </div></div>

If you are saying a hot rodder could have used aftermarket AN fittings back in 69, I agree.
No reason to think GM would have used them. Plenty of 3x2 Pontiac, Olds, and Corvettes before 1969, and all used hard lines.

[iluv69s]

Anyone have a pic of one of these bare intakes?

[earntaz]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lynn</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: earntaz</div><div class="ubbcode-body">As a retired aircraft maintainer, I can tell you stainless steel-braided hose and red/blue aluminum fittings were used on AF jets I worked on back in the early '60s. So I am sure they were used for &quot;exotic&quot; applications such as this 3X2 setup. TAZ <<GRAEMLIN_URL>>/flag.gif </div></div>

If you are saying a hot rodder could have used aftermarket AN fittings back in 69, I agree.
No reason to think GM would have used them. Plenty of 3x2 Pontiac, Olds, and Corvettes before 1969, and all used hard lines.</div></div>

Maybe Smokey was involved ...

[Lynn]

He would certainly qualify as a hot rodder.

[earntaz]

Yep -- old Smokey forgot more than most of em' know ...

[1969HO455]

I thought I would update this post. This intake setup is on a 69 Camaro Z/28 that has been sitting in a backyard since 1984. My friend and I have been after this car since 2016. My buddy was finally able to purchase the car. I asked him to join this site and he will post the full story. The car was purchased by previous owner in the early 70s. He wrote technical books and articles for many automotive magazines and had connections to many heavy hitters in the industry. He built the car and parked it in 1984. The intake he bought from Smokey Yunick in the early 80s while he was at Smokey's shop interviewing him for his Book, Power Secrets with SY. Very cool car.

[Mr70]

I was just thinking about this car earlier this year and was going to bring this thread back up to the top.
Too cool.

[mssl72]

Cool car!!! Fill us in!

[Lee Stewart]

https://i.postimg.cc/MT6y7LPx/0.jpg (https://postimg.cc/p9ShxsM1)

[Lee Stewart]

https://i.postimg.cc/1t3qnqX3/0.jpg (https://postimages.org/)

https://i.postimg.cc/85XrhzfB/0a.jpg (https://postimg.cc/R6fFm9RN)

https://i.postimg.cc/2yqLTN4p/0aaa.jpg (https://postimg.cc/Pvjqrc3K)

[Lee Stewart]

https://i.postimg.cc/Y0JGsD3v/0aa.jpg (https://postimages.org/)

[1969HO455]

Here's a link to more pics from my Facebook post.

https://m.facebook.com/story.php?story_fbid=10159252574929627&id=629704626

[1969HO455]

I helped my buddy pick this up recently. 69 Z/28 purchased by previous owner in the early 1970s. Parked since 1984 in a backyard. The owner, Larry Schreib, published magazine articles and wrote how to books including Smokey Yunick's Power Secrets. My friend and I have been visiting the car and owner for 5+ years and my buddy finally was able to purchase and we hauled it home yesterday. It's got a hi-po built 302 by Gale Banks Engineering's engine guy, Hank The Crank did the crank and special rods and pistons. This special sbc tripower intake setup is one of 3 or 4 developed by Smokey Yunick. The previous owner bought the intake from Smokey in the early 1980's while putting together his book. The car also has a Doug Nash 5 speed, full Recaro interior, and driver's side had these cool Christen Aerobatic aircraft seat belts. Larry also has a set of 15x8 Corvette rally wheels he ran on the car with offset changed to fit car (4.5" BS rear, 5.5" BS front). Cool car.

[JoeC]

this was cool find posted on FB

[dykstra]

Such a cool and unique car. I can’t wait to learn more about it! Thank you for posting!

[SPEEDYB]

Those look like reset 15x8s, very common in the so cal Gulstrand Traco built circle of road racy street cars, Taylor made wheels in south gate ca reset most of them.

[1969HO455]

Interestingly, while chatting again with the previous owner, Larry Schreib, he mentioned he had the car at Gulstrand's shop for some of the work on the car.

[Hotrodpaul]

Angle plug heads too, possibly 340292 turbo heads?

[Big Block 69]

Several, several years ago, One of the major magazines, maybe Hot Rod had a page in the back of each issue called "Quick, What's wrong with this picture?" If you were the first to mail in your answer, I think you got a 1 year subscription. Anyway, in one issue there was a small block Chevy with an intake similar to this one. I don't remember much about it but I think I remember the article saying the carbs had the same spacing as a big block intake so that the factory air cleaner assembly could be used. That was in the 70's or very early 80's so I could be way off.

[JoeC]

Smokey took 3 Camaros to Bonneville in October 1967 and broke a lot of records using different SB and BB combos.

I wounder if he ran the 3x2BB set up there as well as single 4BB and 2x4BB to set some records ?

are there date codes on the Holleys?


https://www.motortrend.com/news/how-smokey-yunick-broke-more-than-300-bonneville-records-with-a-stock-1967-z28/

[solospeedshop]

When Brad & I picked up the Z28 Larry told us a lot of stories One of the main ones was about Smokey he said he would wait till about 5 o'clock to go see Smokey when he was getting info for his books They would hang out to late hours in the morning one day Smokey was busy he said go in and play so Larry was looking around and found the two 3x2 manifolds sitting on a shelf when Smokey came in he asked what can you tell me about those two manifolds sitting on the shelf that look like 3x2 Corvette BB but they are for a SB? Smokey said oh those well those are a piece of shit! I really got a kick out of that as I really like my Z28 I bought and I really like that piece of shit manifold! LOL Bill

[markjohnson]

3-2 bbls has never been the ideal race induction but it survived in legacy just by looking cool. All you have to do is look at 1967-69 Corvettes, when it came to ultimate performance the L88 sure wasn’t wearing the L-71’s 6-barrel induction on top. Looking cool doesn’t win races.

[RALLY]

3-2 bbls has never been the ideal race induction but it survived in legacy just by looking cool. All you have to do is look at 1967-69 Corvettes, when it came to ultimate performance the L88 sure wasn’t wearing the L-71’s 6-barrel induction on top. Looking cool doesn’t win races.

I know of a 67 Corvette with the 427 oval port L-71 Tri-power which runs in the NHRA stock eliminator class that simply hauls. Low 10 second ETS.

[John Brown]

Al Maynard had a GM/Winters/Holley produced small block tri power set-up. I was never successful buying it from him when he was alive. I bid up to $4500 when it was in his estate sale. Still didn't get it. As I recall, it sold for around $6300.

[olredalert]

Al Maynard had a GM/Winters/Holley produced small block tri power set-up. I was never successful buying it from him when he was alive. I bid up to $4500 when it was in his estate sale. Still didn't get it. As I recall, it sold for around $6300.

----My bet would be that Al at one time or another had, at least, one of everything! He was one of a kind,,,RIP, Al!....Bill S

[Gary Anderson]

I know of a 67 Corvette with the 427 oval port L-71 Tri-power which runs in the NHRA stock eliminator class that simply hauls. Low 10 second ETS.

MADISON, Ill. - Final order after 2 rounds of qualifying in Stock Eliminator at the NHRA Camping World Drag Racing Series, 10th annual NHRA Midwest Nationals:

Weather conditions: air temperature 75 degrees, relative humidity 45 percent, barometer 30.05 inches, adjusted altitude 1,716 feet.


Psn--Num--Class-Driver, Home Town, Machine-----------------ET---Index---(+/-)

1 3321 B/SA Marion Stephenson, Williamsport IN, '15 C 10.167 11.25 -1.083
2 L177 FS/C Leonard Lottig, Meyersdale PA, '19 Camaro 9.227 10.30 -1.073
3 5942 FS/C Ryan Montford, Wichita KS, '13 Camaro 9.236 10.30 -1.064
4 507 A/S Lynn Engels, Watertown SD, '67 Corvette 9.906 10.95 -1.044

Just to be clear this is the L68 400hp oval port motor.

[ELEFUNTMAN]

I ran NHRA stock eliminator many years with my 340 sixpak. Made tons of power, many class wins and NHRA records in C/SA, D/SA. Gave everyone fits, they were glad I gave it up. Every time I showed up, “random” tear down. They took the fun out of it. The 3 Holley set up couldn’t be beat, back then anyway! I would love to have the set up on my Z28! :3gears:

[RALLY]

MADISON, Ill. - Final order after 2 rounds of qualifying in Stock Eliminator at the NHRA Camping World Drag Racing Series, 10th annual NHRA Midwest Nationals:

Weather conditions: air temperature 75 degrees, relative humidity 45 percent, barometer 30.05 inches, adjusted altitude 1,716 feet.


Psn--Num--Class-Driver, Home Town, Machine-----------------ET---Index---(+/-)

1 3321 B/SA Marion Stephenson, Williamsport IN, '15 C 10.167 11.25 -1.083
2 L177 FS/C Leonard Lottig, Meyersdale PA, '19 Camaro 9.227 10.30 -1.073
3 5942 FS/C Ryan Montford, Wichita KS, '13 Camaro 9.236 10.30 -1.064
4 507 A/S Lynn Engels, Watertown SD, '67 Corvette 9.906 10.95 -1.044

Nice Vette and quick. Tri-power to boot.

[RALLY]

I ran NHRA stock eliminator many years with my 340 sixpak. Made tons of power, many class wins and NHRA records in C/SA, D/SA. Gave everyone fits, they were glad I gave it up. Every time I showed up, “random” tear down. They took the fun out of it. The 3 Holley set up couldn’t be beat, back then anyway! I would love to have the set up on my Z28! :3gears:

Those 340 engines were strong and quick. And the six pack for sure made it haul. Those carbs helped top end power. Chrysler ran a lot of dual carbs with the 413-426 Max Wedges and Hemi powered engines. The cross ram intakes they designed helped push air and fuel quicker.