Nope, those are '69-'72 service-only big-valve heads; '69Z used 3927186 heads.

------------------
JohnZ
CRG
'69 Z28 Fathom Green

[This message has been edited by JohnZ (edited 02-02-2003).]

 

There were actually two different castings used on the 69 302 in the z28.

As JohnZ mentioned, the 3927186 was used for the 302 in 69.

Also, the 3947041 heads were used as well on the z28 302 in 69.

Both the 041s and the 186s also came on some 350 engines in 69.

------------------
ratchetmaster

1968 RS SS 350 M4
1969 olds 442 convertible
1972 454 ElCamino Turbo 400
1973 RS LT Z28 Camaro M4
1995 Caprice LT-1 WWW A4
1999 Firebird WS-6 T/A A4
moderator http://www.gmforums.com

 

The 3927041 heads did not come on the 302. They are basically the same except for the casting symbol on the front. The 041 head has a triangle and the 186 head has camel back humps. The 186 head is the correct head for the 69 302 engine.

 

thanks for the quick come back...that cleared up some dispute with a friend...they always told me if you really have to know ...ALWAYS CONSULT WITH AN EXPERT........jake....

 

Well,
I don't know where you guys are getting your info from, but . . .

and I can't say this topic hasn't been covered before on here and I missed it,

but the 041 heads were also used on the 302. There have been many documented cars with these heads on them.

Chevrolet by the #s book also covers this topic.

unless I missed something??

------------------
ratchetmaster

1968 RS SS 350 M4
1969 olds 442 convertible
1972 454 ElCamino Turbo 400
1973 RS LT Z28 Camaro M4
1995 Caprice LT-1 WWW A4
1999 Firebird WS-6 T/A A4
moderator http://www.gmforums.com

 

The 186 heads had 2.02" valves, and were the only castings used on '69 302's; the 041 heads had 1.94" valves and were used on many '69 SS350's, 300hp Corvettes, Novas, Chevelles, and passenger cars.

------------------
JohnZ
CRG
'69 Z28 Fathom Green

 

John
I am not trying to be argumentative, so don't take this wrong . . .

But what are your sources for your statements??

I have read several articles (including one in the year one catalogue I believe) and one in a restoration magazine that clearly states that the 041 heads were used interchangeably with the 186s.

They were also both identical to the earlier style 461s except for a redesigned combustion chamber, the temp boss, and the external mounting bosses.

For the 290hp 302 They were fitted with 202 intake and 160 exhaust valves, screw in studs and guide plates, and swirl polished valves just like the 186s.

And another fact . . . the 186s did not only come on the 302s. They also came on 300 hp 350s in chevelles, passenger cars like impalas, caprices, etc; 300hp Camaros, 300 and 350hp corvettes, and novas too.

The only "exclusive" head in this year I am aware of were the 187s which came exclusively on the 350 hp 350 corvettes.

This info comes from what I consider to be one of the best sources of info available . . .

"1965-1969 Chevrolet by the numbers . . . the essential CHEVROLET parts reference"
by Alan L. Colvin.

Now if your source is more complete . . . or can over ride this source of info making this source "incorrect", then I will stand corrected . . . but I don't think so.

[This message has been edited by ratchetmaster (edited 02-04-2003).]

 

Don't believe everything you read in books. A lot of those books were written way before any serious research was done. Some books say X11 could be a Z28. The 186 heads are known as the Z28 head, but they also came in the 350/300 hp engines with the smaller valves. The 041 heads did come on the 350/300 hp engines, but I'm not sure there is any real proof they came on Z28's. If there are any, I'm sure CRG would have them documented as original owner cars.

------------------
Jeff H - Hugger Orange 69 Z28, original factory JL8 brakes, cross-ram & GM fiberglass hood, TI setup, heater and radio delete, Stahl headers, Minilite wheels - being restored - 91 SS454 pickup

 

I don't think screw in studs and guide plates were factory installed on any 302s. Those were added in 1970, on the LT1 as far as I know.

------------------
_________________________
John
'67 SS/RS (RR)
'68 RS conv. (J2)
'68 Z/28 (VV)
'68 Drag Car(ZZ) (in progress)
'73 Corvette Drag Car

 

There are lots of magazines and books out there, written with varying degrees of research, and some of them were printed several years ago and don't benefit from more recent work. If you want the most recent accurately-researched information on '69 Z/28's, Jerry MacNeish's "Definitive 1969 Camaro Z/28-SS396 Fact Book" is the best reference.

Yup, the 041 and 186 heads were used on many other Chevrolet applications as well, in both valve sizes, but only 2.02" 186's were used on '69 302's; screw-in studs and guide plates were used on 186's starting with the LT-1 in 1970, in both Z/28's and Corvettes.

The 187 heads weren't exclusive on 350hp Corvette 350's; both 186's and 187's were used interchangeably on Corvette 350/350's in both 1969 and 1970 (source: NCRS Judging Manuals).

------------------
JohnZ
CRG
Chairman, NCRS Michigan Chapter
'69 Z28 Fathom Green

[This message has been edited by JohnZ (edited 02-04-2003).]

 

I am not sure on the screw in studs or guide plates . . . I am afraid that was my assumption since my 73 Z28 has them. (I believe my engine is called the L82?)

I don't believe everything I read in books. But. . . I do believe what I read from reputable sources . . . otherwise, what or who CAN you believe??

I have heard many supposibly true stories from people which often times were a bunch of crap.

I think this guy (Alan Colvin) did his work and is VERY reputable.
But, then again, I can always take the other side and be a skeptic.

 

John
Just read your post . . .

I would probably bet that "Jerry MacNeish's "Definitive 1969 Camaro Z/28-SS396 Fact Book" is a very reputable source of info. I would be interested in knowing why he has chosen to exclude the possible use of the 041s in 69 z28s. Does He go into detail? Does he feel there are no "authenticated" examples of there use in the 302??
I don't have the book, so I would be interested in what the book says about this topic.

I have found the Colvin book to be very accurate. When ever something is not verified, he puts that in there.

under the 186s info he does say "Please note that the ...041 heads were possibly used interchangeably with this head through 69 and 70 . . . " and lists the 302 and 350s as applications for them.

Then under the 041s he says "This head was interchanged on some . . . 186 and ...187s." and lists the 290hp 302 as an application that was used for this head.

I looked under his "Corrections made" up to his 6th printing and there were no additional comments made or removed from what was already printed on this topic.

also . . . the 187s were only used on the corvette. Other heads came on the corvette. According to CBT#s. I may not have made that clear . . . in other words both sources seem to agree that these heads only came on That application and were not used for other applications.

one more thing . . . the 041 were used on 70 360hp 350 Z28 and the 350hp and 370hp corvette LT1 motors and had 202 valves, guide plates, screw in studs, etc. (1970-75 CBT#s)



[This message has been edited by ratchetmaster (edited 02-04-2003).]

 

Jeff H.
I agree with what you said in your post. Is the registry accessible?? Have there been any 041s? Or are you saying there have not been any registered?
Thanks

 

Colvin did some good work, but his research is old and not always accurate. With more than 19,000 69 Z28's made, I would think that quite a few with 041 heads would have shown up by now. First off, you would need to find a set of 041 heads that are actually 202 valves and a proper combustion chamber. The 186 heads for the SS350 with 194 valves need to have more work done than just putting in 202 valves to make them Z28 heads. There is extra machining that needs to be done to open up the chamber. I don't have any information on the data that CRG is collecting, but I would recommend going to their site and asking the same question. It's a similar situation to all the books that show a 69 302 engine with a 3 digit engine code, they are wrong. There are no known 69 Z28 302's with anything other than a DZ stamped engine.

------------------
Jeff H - Hugger Orange 69 Z28, original factory JL8 brakes, cross-ram & GM fiberglass hood, TI setup, heater and radio delete, Stahl headers, Minilite wheels - being restored - 91 SS454 pickup

 

Colvin's book is not perfect. Very good, yes but not perfect. MacNiesh's book is very good as well but it also has issues. I have discussed this with Jerry myself and he admitted to me that he was still somwhat unsure of some things in the book. I have a couple of known examples. John knows a LOT! Nobody knows it all.

-Mark.

 

I agree, even the books are not perfect. Colvin's state the 388 block was rare, but there have been a lot of examples shown here. Jerry's had at least one reversed number(2) that I found out the hard way. Jerry said he would get those fixed in the next printing.

BTW, I agree that the 041s were on SS350 plus others, 186 was on SS350s plus Z/28 (but only in 1.94 size). A true 2.02 186 was only on Z/28s, cause 041s did not come in 2.02 size from the factory that I have ever heard of.

Kevin

------------------
69' SS-350 Convert, M20, 3.55 posi. Totally Disassembled & in boxes (I'm working on it!)
69'(Hugger Orange -originally, Burgundy now) Z-21 Convert 327/PG, 3.55 posi too! Driver

 

I have never seen a documented 1969 Z28 that ever had the 041 head in it. The 186 head was the only head used in the z28. There are mistakes in the books mentioned above. I have never seen a triangle symbol on the front of a head on an orignal DZ engine. John Z was there at the Plant.

I would say the burden of proof is on the person who says 041 were installed.

 

It is not a registry, it is a database.
Not one single example of a 69 Z with 041 heads has ever been found. All have 186 heads.

And Alan is supposed to update the 388 block note. It was at least as common as the 386 block.

------------------
Kurt S.
CRG www.camaros.org

 

Just a little FYI, the "186" with 2.02 valves was also used in the 69 Corvette 350/350 HP L-46 engine. That was the highest horsepower Corvette small block option for 69.

-Mark.

 

ok . . .
So we seem to have established that the references are not verified in CBT#s. And that although there are many "good" sources of info, none are completely accurate. And it seems that CBT#s is NOT as accurate as I was led to believe.

Mortec.com also lists the 041s as 302 heads . . . and I have been told they are not totally accurate either.

Anyone know Alan personally or have an email for him?

I don't know what the date was of his most recent revision or reprint, but the back has the corrections listed and none have been made with reference to the 041s as if the 6th printing.

So have there been verified 041s on 1970 Z28 350 engines?
Or is that wrong too?
I will post this question at www.gmforums.com
and at a couple of other sites that cover end gen camaros as well.

I have a set of 041s that are the 194s. I have never personally seen one with 202s.
They are small chamber (~64cc)and mine have screw in studs but were aftermarket for sure.

Which plant was John at? norwood, van nuys, or an engine plant?


[This message has been edited by ratchetmaster (edited 02-05-2003).]

 

web http://www.chevroletbythenumbers.com/index2.htm

email
alancolvin@bigplanet.com

FWIW you can get updates to his books from the web site.

 

<BLOCKQUOTE>quote:</font><HR>Originally posted by ratchetmaster:
one more thing . . . the 041 were used on 70 360hp 350 Z28 and the 350hp and 370hp corvette LT1 motors and had 202 valves, guide plates, screw in studs, etc. (1970-75 CBT#s)
[This message has been edited by ratchetmaster (edited 02-04-2003).]<HR></BLOCKQUOTE>

Although the 041 heads have been shown in print as "possibly interchanged with 3927186" heads, not one has ever been documented as original on 1970 LT-1 Corvettes, and their only documented usage on any Corvette was on the 1969 350/300hp engine.



------------------
JohnZ
CRG
'69 Z28 Fathom Green

 

<BLOCKQUOTE>quote:</font><HR>Originally posted by ratchetmaster:
Which plant was John at? norwood, van nuys, or an engine plant?
<HR></BLOCKQUOTE>

All of the above, and many more - 21 years with Chevrolet Engineering and Manufacturing (1964-1985).



------------------
JohnZ
CRG
'69 Z28 Fathom Green

 

John
you are the man!!

I am sure that there are other "errors" out there . . . you should be paid as a consultant and get things fixed with all these info sources.

(Tim inserts foot in mouth for thinking that he actually learned something in his 41 years on this planet . . .

)

secndgn
Thanks for the link.

[This message has been edited by ratchetmaster (edited 02-06-2003).]

 

I've just collected lots of references over the years, hung onto them as part of my tech library, and I try and cross-check against at least three of them before I respond to a question unless I've researched the issue before; if I'm not confident I can answer the question accurately, I just wait and learn something new whenever I can. 37 years in Engineering and assembly plants didn't hurt, either

------------------
JohnZ
CRG
'69 Z28 Fathom Green