First a little background on my situation here. I did a little horse trading yesterday and now I own a 71 truck. It has double hump heads on the motor now, which seems to run very well. The guy I did the trading with wants to keep the heads and give me another set of heads, that are not double hump, to install. The deal is he'll help with the head swap and we use his shop. My questions to you guys are, #1/what makes these heads so special, #2/what are they worth. #3/Should I try to keep the heads? Thanks for any input guys. Brian

which seems to run very well If it ain't broke, don't fix it.

1. They were the general performance head of choice before the arrival of the aftermarket heads.
2 They are worth whatever someone will pay for them, and eBay is a good place to see what people are paying. Find a guy who needs the casting dates to complete his matching motor and they can be quite valuable.
3. "which seems to run very well" If it ain't broke, don't fix it.

DOUBLE HUMP MEADS- what are they?
Beats the hell out of me! :confused: ;)

Fuelie heads? Were they used on Corvettes?

Is the horse power that much different the other stock heads?

double humpers or camel back heads(2.02 fuelies) came out in early 60's and were a 2.02 head. They were the answer to hi po small blocks especially the 327(1.94 fuelies was the GM hi po head before that). They came with higher lift(back then called heavy duty) springs to allow camshafts like the corvette 30/30 and early fuel injection to make more hp and better breathing. When I built my 1st car(68 Camaro) in 76 you could buy them new or rebuilt for about 100.00 for the pair, ready to slap on. Now days I have seen a good set with #'s not ground off go for as much as 1200 , and a bare set needing work for 800.00.

If you want to keep them for a #'s matching it is well worth it, and these heads are very good to port, lots of cast.

thanks

Lets think about this. If he wants to give you a set of -041's for them, go for it, imho..

Same head but doesn't have the double-hump and they also have bolt holes on the ends of the heads.

But first take the time to check what the casting numbers are, (the three last numbers like this -462), and the cast date code and somebody will tell you what you have.

It should be right under the casting number and like this "E 17 5" or something like it??? That decodes like May 17, 1965??

pdq67

Do you want the FULL background story on "double hump" heads, or is the above enough info to satisfy your question?

I am against disassembling a good running engine. The legend of the double hump camel back heads dates from the era of no aftermarket heads. Time has not treated them well in the production of power - every single aftermarket head will make more power. Why don't you see how valuable those heads are to the seller. Maybe instead of the 041's he would give you cash that you could apply toward new aftermarket heads. Otherwise the 041's are good enough heads.

Thomas

I would like to know Tom

double humpers or camel back heads(2.02 fuelies) came out in early 60's and were a 2.02 head. They were the answer to hi po small blocks especially the 327(1.94 fuelies was the GM hi po head before that). They came with higher lift(back then called heavy duty) springs to allow camshafts like the corvette 30/30 and early fuel injection to make more hp and better breathing. When I built my 1st car(68 Camaro) in 76 you could buy them new or rebuilt for about 100.00 for the pair, ready to slap on. Now days I have seen a good set with #'s not ground off go for as much as 1200 , and a bare set needing work for 800.00.

If you want to keep them for a #'s matching it is well worth it, and these heads are very good to port, lots of cast.
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This is close but.
Here is the best I can do from memory,,,
Almost all camel hump heads regardless of casting ID have the same basic port configuration.
This is with the exception of the 461X head which was about 10cc larger.
This is a very rare head & you will find 461 heads with an X cast in the valley side on the opposite end of the 461 number.
To the best of my knowledge these are not the 461X head.
The real 461X will have the X with the number. This gets a little foggy,,,
461`'s have the full quench pad on the plug side of the chamber.

From 462 on this is relieved & the plug is raised some.

All 2.02 x 1.600 heads came with screw in studs & guideplates from the factory.
The 1.94 x 1.5 "camel hump heads" did not come with the screw-in studs & plates, again from the factory.
The 2.02's came on Z28 Camaros, 350HP 327's, & the 340, 360. 365 & 375HP rated 350's
The 275 & 300HP 350's came with the 1.94 camel humps.

The casting number were 461 the "original "fullie" or "camel hump" which came on early Corvettes & can have either size valve.
462 again came in both 1.94 or 2.02 depending on application with a slightly different chamber shape.
291's, same as 462
186, same as above with accessory bolt holes
492, latest 64cc head installed on a car & is or was also the head sold over the counter by GM.

This is all I can remember so I will let Tom continue or correct any mistakes as he is a wealth of info on this stuff :)

All 2.02 x 1.600 heads came with screw in studs & guideplates from the factory.
The 1.94 x 1.5 "camel hump heads" did not come with the screw-in studs & plates, again from the factory.
The 2.02's came on Z28 Camaros, 350HP 327's, & the 340, 360. 365 & 375HP rated 350's
The 275 & 300HP 350's came with the 1.94 camel humps.

The casting number were 461 the "original "fullie" or "camel hump" which came on early Corvettes & can have either size valve.
462 again came in both 1.94 or 2.02 depending on application with a slightly different chamber shape.
291's, same as 462
186, same as above with accessory bolt holes
492, latest 64cc head installed on a car & is or was also the head sold over the counter by GM.


To my knowledge the 1.94's were never classified as double or camel hump heads, only the 2.02's and were identified by the double hump stamping on the front of the head. Yes different castings were made as they progressed.

1.94 fuelies are not to be cofused with the double humpers, and yes were available on many of the early sbc's. All true double hump heads came from the factory as well as the 1.94 fuelies. Fuelies refers to the heads being produced to go with chevy's early fuel injection, and were later used by hot rod enthusiasts, etc.

At any rate if you have a pair, keep em use em and enjoy

To my knowledge the 1.94's were never classified as double or camel hump heads, only the 2.02's and were identified by the double hump stamping on the front of the head. Yes different castings were made as they progressed.

1.94 fuelies are not to be cofused with the double humpers, and yes were available on many of the early sbc's. All true double hump heads came from the factory as well as the 1.94 fuelies. Fuelies refers to the heads being produced to go with chevy's early fuel injection, and were later used by hot rod enthusiasts, etc.

At any rate if you have a pair, keep em use em and enjoy
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This is incorrect.
The 202's & 1.94 in various configurations used the same exact castings.

All double hump heads came with both 202 & 1.94 valves at one time or another.

I have at least three sets of 1.94 double hump heads sitting in my shop & they all have 1.94 seats.
In fact the majority of double hump heads are the smaller valve.

These are my head of choice for restricted circle track deals as I can reconfigure the seats to my liking & "extend" the valve job with 2.02 valves when no porting is allowed.
I have been doing this for a long time & have done a number of sets of these heads so trust me, the double hump casting does in fact come with the smaller valves :)

I think some of the early double-hump heads are even cut for 1.72"/1.50" valves too.

My -461's have stock big valves and I pulled the studs and installed threaded studs but did not touch them anyplace else so they are to me still virgins except for threaded studs.

pdq67

I stand corrected, thank you for pointing out the error of my ways.
It's nice to have such a knowledgable head man.
I thought I had some idea.

Off topic...

I contacted Ed at Mortec to find out what head was on the 315hp/283 FI motor b/c I didn't know. He said it was a 1.94"/1.50", -461X jobber!

pdq67

thats what I like about this site.... if you just sit back & watch for a while the whole story makes it to the page :) cammel humps were good for their time ... but its 40yrs old now a set of vortec's cut for more cam lift will out flow em by a long way & cost less to boot !! but then the guys at the drawing board back then didn't have anywhere near the computer power or flow bench tech we've got now ;)

Double Hump heads are good but they are not the best heads available since Chevy built the Vortech heads.

- What is the casting number of the heads he wants to put on the truck?

- Does the truck run on Super Unleaded fuel now?

There are lots of reasons to use the double humps and there are lots of reasons to not use them. I know that does not hlep but that is the truth.

All 2.02 x 1.600 heads came with screw in studs & guideplates from the factory.

While I think this is true in the context that you are using it, it should be noted that I have personally rebuilt a set of 186 heads from an original 1969 Corvette. It had the 350hp 350. They had 2.020 intakes and 1.600 exhaust valves, but no guideplates or screw in studs. The customer had me convert them.

Nate

I THINK? that screw-in studs and guide plates started in '70-1/2 with the 350 LT-1 motor if not mistaken.

pdq67

While I think this is true in the context that you are using it, it should be noted that I have personally rebuilt a set of 186 heads from an original 1969 Corvette. It had the 350hp 350. They had 2.020 intakes and 1.600 exhaust valves, but no guideplates or screw in studs. The customer had me convert them.
I don't know if you can group the 1969-70 186 heads with the earlier double hump heads. The humps look different. Smaller, shorter and further apart.

Anyone ever seen an 040 head ?
I have one.


Nate
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Hi Nate,
First as I said what I posted was from memory which tends to get a bit fuzzy at times,,,
You are correct, I should have said almost all 2.02's had screw in studs.

I should know better than to ever say "all" when it comes to GM :(
And yes, I have seen 040 / 041 heads but left them out as I have seen maybe one or two sets in the last 30 odd years,,, and they were not marked with the "double hump" as I recall. Had a different marking.

The 186 is still a double hump, just from a "smaller camel" :D
They also had accy holes.

======
Paul,
Far as I know all Z28's had screw in studs so this would put them back to 67.
But again, never say never when it comes to GM,,,, :clonk:

To those that have posted about this head being outdated,,, true & this may seem like a lot of information about a 30+ year old head that can be replaced for less money by much better heads these days but they still do have their place :)
It is the head of choice when you have to use them in some classes that require stock GM castings.
And,if you were restoring say a numbers matching 69 Z28 & highly doubt you would be buying newer better heads for it :D

040 heads aren't that hard to find... I see em every time I open the hood .. marking is a square with a /I on the top of it they came as 194 or 202's only made in 68

"DOUBLE HUMP MEADS- what are they? "

A pair of Hump heads?

He, He, He!!

Sounds like something a "Wood-Hippie" would be looking for!!

Page 113 in HPBooks "How to Hotrod Small-Block Chevys" say's the screw-in studs came out with the 70 Z-28 motor Mike.

That's all I have to go by Mike.

pdq67

PS., guy's, I'm telling you there is a wealth of old info in both the SB and the BB HPBooks!!

have you guys heard the song.. my humps... from black eyed peas... heh

He, He, He!!

Sounds like something a "Wood-Hippie" would be looking for!!

Page 113 in HPBooks "How to Hotrod Small-Block Chevys" say's the screw-in studs came out with the 70 Z-28 motor Mike.

That's all I have to go by Mike.

pdq67

PS., guy's, I'm telling you there is a wealth of old info in both the SB and the BB HPBooks!!
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Paul, you can't take everything your read in those books as gospel,,,

This is not out of any book but,,,
I had a DZ 302 in 69 & it must have been confused or didn't read your book as it for sure had screw in studs & guideplates :D

And, it for sure started life as an all original DZ 302 not a 350 which the 70 1/2 was.

It was originally equipped with the cowl induction hood, DZ engine, 4speed, 4.10 gears, limited slip 12 bolt, all directly from the General.

I wacked it up & made a race car out of it :rolleyes:

OK, now that we've had all the "I think", and "maybe", and "as I remember", here is the history on the "double hump", or, as ORIGINALLY known, "fuelie" heads.
In 1957, Rochester fuel injection was an available option on the 283, both pass car and Vette. The last year for FI on pass cars was 59 and the last year for FI on Vettes was 65. The 57 283s in pass cars with a 4bl carb ("Power Pack" heads) had the exact heads, with the pyramid symbol on the ends, as the Vettes with FI, they were 539 heads. The 539 heads, even though used on the 57 Vettes with FI, are not particularly valuable because as I mentioned, thousands of 57 pass cars with a 4bl carb also used the same head. No big deal. As everyone knows (or you SHOULD know) the 57 FI engine with solid lifters was rated at 283hp-----ONE HP per cubic inch----------------a BIG deal for Chevy back then. The FI, or "Fuelie" head term had not really caught on---------------------YET!
In 1961, the 283 with FI made a major jump in power output, up to 315hp. THIS WAS A VETTE ONLY ENGINE! The 61 315hp 283 came with the 461 heads--------------------AND THEY HAD DOUBLE HUMPS!!! NOW, these heads with the 2 hump symbol on the ends DID catch on as
"Fuelie" heads, because they were VETTE ONLY and FI ONLY. This was the VERY BEGINNING of the "Fuelie" head term that related to a specific head. It stuck, and, for the most part, at least for us old timers, has stayed. You young whipper snappers don't have a clue about some of this old Chevy history. These "fuelie" heads with the double humps, camel humps, whatever you want to call them, had 1.94 intake and 1.5 exhaust valves, ONLY, up through 1963. In 1964, THE SAME HEADS CAME WITH EITHER 1.94/1.5 or 2.02/1.6 VALVES. The sizes of the valves was totally dependant on the HP rating of the engine beginning in 1964. The 64-later 300hp/327 got the 1.94/1.5 valves. the 360-350-375hp/327 engines got the 2.02/1.6 valves. FROM THE FACTORY, the heads that were machined for and received the bigger valves also were machined along the combustion chamber wall next to the intake valve to unshroud it and improve air flow around the head of the bigger 2.02 valve. This is a super easy way to immediately spot a head that originally had 1.94 valves and was later machined to accept the bigger 2.02 valves-------------------------------except for the guys like me who also had the machinist relieve the chamber wall so that no one would know they were originally 1.94 heads. From 61 to 68, there were about 4 head casting numbers with the PLAIN ends and double humps. Even though 1961 was the ONLY year that double hump heads were unique to ONLY the FI engine and after that, they were used on both FI and carb engines, the term "Fuelie" head has just stuck.
There are numerous examples of terms that stuck which were not intentional. The VERY BEST example is the now famous Z/28. Z28 was NOT ORIGINALLY a model of a Camaro, IT WAS AN OPTION DESIGNATION! But, it was so immediately popular that Chev capitalized on it. The L88 was an engine option and it stuck. The L84 (FI) was also an engine option, it didn't stick. But L79 stuck in Chevelles-Novas-Vettes. Everyone knows what a ZL1 is, but who knows what a ZL2 is???? Why? Who knows!
In 1969 and for a few years later, the heads used on the SB medium and hi-perf performance engines continued to have the two hump symbol on the ends of the heads. But, because 69-later heads now had the holes and machined bosses on the ends, those two humps were not as predominant as they were on the 61-68 heads-----------------and fuel injection was long gone. So, the term "fuelie" heads began to weaken and "double hump" or "camel hump" began to be more commonly used.

SCREW IN STUDS AND GUIDE PLATES
FROM THE FACTORY, screw-in studs and guide plates were first installed on 1970 (Z-28 and LT-1 Vette) engines. Both were IDENTICAL 350 engines. The Z-28 was rated at 360hp and the LT-1 Vette engine was rated at 10hp more, 370hp. The reason the Vette engine was rated at 370hp was supposedly because it had a more free flowing exhaust system. Again, who knows? THESE WERE THE ONLY 350 ENGINES that got screw-in studs and guide plates-----------------specifically because they had the highest lift, production solid lifter cam of any SB engine. The last year for a solid lift SB cam was 72, but the optional Vette engines with hyd cam and Z-28 (also hyd cam) engines continued to get screw-in studs and guide plates.
Up through 1970, the heads had about 64cc chambers, then, in 71 the bigger 76cc heads were used across the board on all SBs (some late 60s lo-perf engines, such as the 307 had 76cc heads and small valves, kind of worthless!).
Even though the 71-later heads got 76cc chambers, they are still a good choice for 350-400 engines with today's gas. BUT, keep this in mind--------------THE LAST GOOD SB HEAD WAS USED ON THE 74 ENGINES. Beginning with the 75 models (casting dates beginning about Jul-Aug 74), the SB heads (especially 30yrs later) are, in my opinion, junk. The reason is because with the 75 model SB heads, Chevy started cutting corners, removing metal and added a second exhaust crossover passage. By 1977, the SB heads were "paper thin". If they haven't cracked by now, I promise you that if you have a set of 75, or at least 77-later SB heads and have them rebuilt, you are really asking for a crack(s) to occur soon. The deck of these heads are already thin and if your machine shop surfaces them, they will be even thinner. NOT GOOD! So, for rebuilding a SB engine with STOCK heads, stay with 74-earlier castings.

So, lets get back to the EARLY double hump heads. Are they any good. Sure, they are fine for a medium-perf engine, especially if they are 1.94 heads and you open them up to 2.02/1.6 valves and have the chamber relieved next to the intake valve. Also, it will help to have the intake runners port matched, have the bowls and chambers cleaned up. NOT A FULL PORT AND POLISH THROUGHOUT, just cleaned up. No, they WILL NOT flow like any of the aftermarket heads, but they will make good heads. Also, if you have a pair of 35+yr old heads that you want to use, spend the money to have them vatted and magnafluxed first to detect for cracks before you start spending REAL $$$$$ on them.

Tom,
I knew you would give a history lesson :D

Only thing I am going to disagree with is I know for a fact that I had a 69 DZ Z28 & it for a fact had studs & plates.
This is not out of any book or from anything I read on the internet this is an engine in a car I owned.

As I have said before, you never want to say never say never with the General,,,

Mike,
I should have qualified that, because SOME people with GENUINE 69 Z/28-302 engines have stated that the heads had guide plates and screw-in studs. And, it is quite possible that some did. UNFORTUNATELY, I've not seen the valve covers removed from every 69 Z/28 engine built! But I've adjusted lifters on several that did not.

Mike,
I should have qualified that, because SOME people with GENUINE 69 Z/28-302 engines have stated that the heads had guide plates and screw-in studs. And, it is quite possible that some did. UNFORTUNATELY, I've not seen the valve covers removed from every 69 Z/28 engine built! But I've adjusted lifters on several that did not.

This I can agree completely with & thanks for taking the time to go back to the beginning before double hump fuelies,, to the original "power packs".

Also, thanks for the correction that all 2.02's had screw in studs as I realize that was incorrect,,, so I will go with all 2.02's from 1970 on had,,,, never mind,,

As I said,,, with the General never say never :D
And going from memory has it's disadvantages,, been doin this stuff too damn long & never was real good with trivia anyway,, :rolleyes:

WOW!!! Thanks for all the info guys, much appreciated!

Tom,
I knew you would give a history lesson :D

Only thing I am going to disagree with is I know for a fact that I had a 69 DZ Z28 & it for a fact had studs & plates.
This is not out of any book or from anything I read on the internet this is an engine in a car I owned.

As I have said before, you never want to say never say never with the General,,,

I believe some 69 Camaros were built in early 1970 !

This may explain why some have screw-in studs and some don't. Early vs late builds.
A 69 Z/28 Camaro built in September-December of 1969 may have used heads slated for the 1970 production, thus having screw-in studs.

Mike,
be sure you know that I was not trying to point out that you were wrong. Not at all. I was just adding some information that I thought might be relevant. I tried to word it so as not to offend you.

Tom,
unshrouding, relieving, or what I usually call flycutting is done on all kinds of heads when installing bigger valves OR to decrease compression. I'm very familiar with the machining process. I've done many.:)

The older Pontiac heads are interesting to look at. Their chambers are machined. I'd sure like to see footage of just how this was originally performed. I know I can't duplicate the swept-in bowls.

Nate

I believe some 69 Camaros were built in early 1970 !

This may explain why some have screw-in studs and some don't. Early vs late builds.
A 69 Z/28 Camaro built in September-December of 1969 may have used heads slated for the 1970 production, thus having screw-in studs.

Mike,
be sure you know that I was not trying to point out that you were wrong. Not at all. I was just adding some information that I thought might be relevant. I tried to word it so as not to offend you.

Tom,
unshrouding, relieving, or what I usually call flycutting is done on all kinds of heads when installing bigger valves OR to decrease compression. I'm very familiar with the machining process. I've done many.:)

The older Pontiac heads are interesting to look at. Their chambers are machined. I'd sure like to see footage of just how this was originally performed. I know I can't duplicate the swept-in bowls.

Nate
=
Hi Nate,
No offense even considered:D
We all learn stuff every day & I expect to be corrected if I make a mistake,, I hate misinformation,, worse than no information.

The 69 I was referring too was a mid to early 69 as I bought it in the middle of the year.
It had been stolen & partly stripped but was recovered with all the original parts & I ended up with it for the high bid of about $1500 :cool:

It came with almost everything, except the hood, intake & carb.
Apparently the guys got caught in the middle of their "project'
I built it with a Rat which went through a number of iterations & put the 302 in a 63 Nova with the factory fuel injection.

Here is a 30+ year old pic for your nostalgia gallery,,,

http://wsm.ezsitedesigner.com/share/scrapbook/19/190264/Camaro_2.JPG

Great thread!!

And some more history.

My -306 closed chambered, sparkplug troughed, '56, 265 heads measure about 120 or so cc intake port size and have 60 cc chambers and small 1.72"/1.50" valves.

Powerpack heads, I read are about 137 or so cc intake ported, same valves and squared off open chambers.

And a VERY good newer head is the 305HO, -601 head if you ever get your hands on one and look it over. (Moreso for smaller motors here tho).....

1.84"/1.50" valves, hardened seats, double-quench, more rounded, bean shaped chamber similar to the original -461 head, 160+ cc intake ports and chambers sized from 53 to 58 cc's so you NEED to cc them to know for sure.

Great heads for the smaller motors, imho..

pdq67

I have some of the #601 305 heads, but they look like awfully thin castings. Are they really any better than any other 305 head, (on a 305).??

Nate

Who cares??? Its another one of those numbers gear head guy things a guy says to look cool. If your spending that kind of cash on a mild small block save your money. A guy asked me the other day "Do you have small block 202 double hump 6 quart "383 stroker" 215 750 double pumper in that thing?" I said No its a 4 banger.....LOL