camel hump heads [Archive] - Chevelle Tech

: camel hump heads

Nov 2nd, 98, 7:25 PM
Can anyone shed some light on any differences between the #461 and #462 castings? How about prodution years and models they are found on? I have some of each (for sale) and an interested party asked these questions. I feel obligated to give an intelligent answer (in this case, so I post the question here knowing I'll get the best info to pass on. Thanks in advance, Bryan

Nov 2nd, 98, 9:49 PM
I can tell you about the 3890462 casting, but I have limited info on the 3782461.

The 462 was available with either 1.94" or 2.02" intake valves and was a 327 only head from 62-68 except for the 302 in the 67 Camaro Z28. It is mainly considered a hi perf head, but was also used on the trucks and fullsize passenger cars. If these heads have the 2.02 intakes, most likely would be a hi perf head and if equipped with 1.94 intake valves would be the less desireable low perf heads. Some have chambers as small as 60.5cc, but 64cc is the hi perf version.

The 3782461 first came out on the 283 in the 61 Vette and was also used on 283s and 327s in almost all lines of chevy cars from the ChevyII to the fullsize passenger cars and trucks. That is all I can tell you about that one.

With that said, the 462 sounds like the better of the two, and should be worth more, if you have the hi perf version. Both heads should have no accessory bracket holes in the ends and no holes for temp sending units and flat spark plug seats for the large plugs (13/16 socket). Hope this helps

[This message has been edited by Scooter (edited 11-03-98).]

Nov 2nd, 98, 10:13 PM
Here's an added zinger; One pair of these heads have an "X" after the casting #. Don't remember which one, 461 or 462, but I think it's the 461. I also heve a set of 292? castings with the same "X". Anyone know about the "X"? Bryan

Tom Mobley
Nov 2nd, 98, 10:54 PM

The 461 and 462 are very similar, the main difference on the ones I've seen was that the 461 had a smaller chamber. It has an extra quench area on the spark plug side of the chamber.


461x heads have a 10cc larger intake port. It'll run about 170cc as cast. Very desirable for certain NHRA Stock class racers. The x is visible thru a water jacket core hole on the deck side. The currently popular World Product S/R heads are about this size. FWIW, YMMV, all that.


Tero Toppila
Nov 3rd, 98, 5:08 AM
I got to tell you this: Iīve measured most of these camel hump heads (#186, #291, #461, #461x...) intake ports myself last winter, and they really were all the same. ALL OF THOSE CASTINGS MEASURED 165cc, INCLUDING THAT #461x.

I located tens of pairs of these old camel hump heads just by accident from a wrecking yard, and I was wery eager to return there again and measure them to find a superior head for few dollars. You can imagine my disappointment when I finally got to measure the intake ports, and they all were the same! Really! The intake port from a #461x is just as small (approx. 165cc) as from a #291, for example.

I had read from Hot Rodding magazines that there are some superior big intake port camel hump and fuelie heads cast by GM, and I thought they were either #461x, #292 or both. So now I know the superior head definetely is not the #461x...

On the latest Chevy High Performance Magazine there are quite many SB Chevy heads measured (both the intake ports and combustion chambers), and they even flowed them on a flowbench. Itīs a VERY good article! One camel hump head was there, namely the #492. Their measurement did not end up as big as mine, I think they got 159cc, but Iīm not sure. Gotta check that article again. Anyway my measurements are from stock heads, not ported, so what could be the difference between the magazineīs and my measurements? My measurements may be off by 1-2cc, but no more.

That wrecking yard I visited has got various types of those camel hump heads lying around. Ported, stock, with valve seats installed and without, small and big valves, screw and pressed studs, complete and bare, some cracked, some not... They cost less than $300 a pair. That may sound like cheap, but I wouldnīt install any of those heads straight without first checking (and maybe machining and fixing) them.

And to answer Bryans question: the main difference (in my opinion) between a #462 and a #461 (x or not) is the combustion chamber size. The #462 has got the normal approx. 64cc chamber and the #461(x) has got a bit smaller one with approx. 60,5cc. Just as Scooter said. So with the same pistons you get more compression (=power or problems...;) with the #461(x) heads.

Bryan, you said youīve got #292 heads there. PLEASE VERIFY THE INTAKE PORTS OF THOSE AND THE #461(x). Put an intake valve in itīs place in both heads and check which headīs intake port will swallow more water. By doing that you could end this never-ending debate about mystery GM SB heads! Please do that and try to be accurate. No accurate cc number is necessary, just the fact whether they are the same size or not.

I mean you could do me a BIG favor. Iīve been searching those "mystery" big port heads for some five years every time I went to a swap meet or wrecking yard, and Iīve already given up because I thought the best ones were the #461x castings. But what if the #292 is the one? You would send me on a mission again by telling me that #292 intake port is clearly bigger. I donīt care how much bigger, just the fact would put me on the road again..... ;)

Million thanks already.

Andrew Crooks
Nov 3rd, 98, 9:18 AM
Man, I had a set of those 292 heads last year that I picked up all finished and ready to go. New springs, Hard seats, stainless valves, the whole 9 yards. Not to mention a port job to rival a set of BBC heads. I was going to put them on my 350 in my chevelle then relized I didn't have a big enough cam to flow the heads well enough, and I really wanted to but a big block in it anyway. I ended up selling them to a good buddy of mine that was building a 350. 10:1, with one of those 234/244 @.050 summit cams. He put the motor in a 65 chevyII and MAN DOES IT GO... I have another friend that has a similar motor (same cam) but just pocket ported 882 and it doesn't go nearly as well as the 292 headed motor. Anyway the 292 head was I believe the LT-1 turbo head from 70 or 71. It came with straight plugs on production motors, BBBUUUTTT The over the counter 292 heads that you would buy from the parts desk were angle plugs. They must have known back them that angled was better. The heads that I had were the angle plug heads and I have yet to run into anyone that has the angled plug heads also. ONE LAST THING I CAN'T REMEMBER HTE EXACT SIZE BUT WHEN I GOT THE HEADS I DID SOME RESEARCH AND FOUND OUT THAT THE 292 DO HAVE BIGGER INTAKE PORTS.

[This message has been edited by Andrew Crooks (edited 11-03-98).]

Tero Toppila
Nov 4th, 98, 1:44 AM
That was good information, Andrew!

If yor pal ever pulls the heads off, convince him to measure the intake ports carefully, even if they have been ported. And the ultimate thing to do would be to flow them on a flowbench, but that may be too much asked...

By the way, WHERE did you find the information that the intake ports from #292īs are bigger than other headsī?

Anyone other out there with experience or knowledge on these #292 castings, angle plugs or not??????????? Join the discussion in order to get this "mystery head" thing sorted out. Any fact will do!

Nov 7th, 98, 10:40 PM
OK; 1st thing, I've got to apologize Tero. What I found in my garage is not quite what I thought it was. Didn't mean to give you bad info, sorry.
What I've got is a pair of 291(z)castings, 2&1/2 pairs of 461(no X), a pair of 462's on a motor, and a pair of 041X castings.
For whatever it's worth, I made some rough measurements. I tried to be as accurate as possible, but I'm not real confident with the results. Here's what I found:

#461 170cc int. 60cc chamber (1.94)
#291 150cc int. 65cc chamber (2.02)
#041X 160cc int. 60cc chamber (2.02)

The 041X heads are complete. I beleive the weird volumes in the #461 & 291 heads are due to using the only spare valve I had on both heads. It was a 1.94" valve that sat unusually high in the 461 head and barely sealed the big valve 291 head. It went in DEEP! Further, my graduated cylinder was made from a baby bottle with 50cc graduations that I divided into 5cc units by adding fluid from a medicine dropper and scratching lines. Not very scientific.
On a positive note Tero, have you considered 041(X) heads? They've got decent #'s and accessory holes. They were used in '68-'71(?) 302,327,& 350 perf. engines, and are probably as good as any of the "camel humps". Sorry for bad info on part #'s, I'll make a real effort to be more accurate in the future. Bryan

Nov 8th, 98, 1:22 AM
Ok, this info is straight out of a book available at your local bookstore, on modifying cylinder heads. The 461 head was cast from 61-66, in both small and large valve versions. It was used on 62 fuel injected 'vettes, thus picking up the "fuelie" nickname. The "x" versions had port sizes of around 175cc, up from 158-160 for the regular 461's.

The 462 castings were offered from 66-68, in both small and large valve versions. The plug location was higher than the 461's, enabling higher domes on the pistons, thus enabling higher compression.

The 291 castings were mainly produced in 68, although a few may have been used in 67/69. Basically identical to the 462.

The 040 castings are rumored to be a direct copy of a 291 or 492 casting, and may have been used on trucks through 68. Funny thing, I have a set of these, and can't find any other info on them.

The 186 castings came out between 68 and 72, basically the same as the 291's and 462's, although they have less material under the spring seats, and have accessory bolt holes.

The 041's were identical to the 186's, though with more material under the spring seats. Offered in 69-70, on 350's. Has a triangle, instead of double hump.

Last, the 492. Offered in 69-71, on high performance 350's, and as a service replacement for the 64cc heads. Basically the same as the 186/041, and supposedly still available at your local chevy dealer, under different p/n's. Later castings offered 1.44" diameter spring seats, and thicker spring seats.

I have the aforementioned 040's, 2 pairs of 291's, (1 set 1.94's, 1 set 2.02's), and a set of 461's (1.94's). I haven't tried the 040's, but on a 327, the 461's were king. The 291's were okay, but even the 2.02's couldn't match the 461's. Now, I have some Dart 200's, on a 383, but that's a different story. Hope this info helps. Darren

Nov 8th, 98, 5:08 PM
Just to add a little more to the above; the 292 angle-plug castings(a.k.a. Turbo) were never offered on any engine package as they were strictly an off-road item. In 1975, I bought a pair of bare castings over the counter for my 406" powered Vega SuperPro bracket car.

Tero Toppila
Nov 9th, 98, 7:11 AM
Gee, guys, weīre really getting somewhere, bit by bit ;)

Great that you measured all those heads, Bryan. I think the #291 measurement suffered from that super sunken small valve, thus making only that few ccīs. And our #461 measurements were about close enough from each other to let us trust those numbers.

Thanks Cameano for providing all the data from that book of yours. I just donīt get it how could I measure the #461x as low as 165cc, maximum! Could there be different kinds of those x castings? Well, who knows.

All the heads I measured (#186, #291, #461 #461x) were in a couple of ccīs range, and I got both the 2.02" and 1.94" valves with me. Ok, my measurements might be off couple of ccīs, but NONE of those heads exceeded 165cc, really.

I also saw couple of pairs of those #041 castings with the triangle casting mark, but didnīt measure them...

Clint44, Iīm building a 406, too, so how did your #292 equipped engine run? What other parts did you put there? Where are the heads now? Do you remember whether they had angle or straight plugs? Are they still "alive and kicking"?

By the way, Darren, did you ever had any camel hump heads on your 383 before those Dart 2īs. I mean was there any real difference between those heads? At least the Darts should flow better, or what? Experience, anyone?

Hey, anybody out there with #292 angle plug heads? This "mystery head" thing is still open....

Nov 9th, 98, 10:52 AM
Man, this is enough to make your head spin...

Okay, my two cents. One more application for the 462 castings was the 1967 350. It was Camaro only, and was the only 350 ever built without accessory hole heads. The shortblock was basically the same as the big main 327 (and even the later 307), except the crank. The heads had the small valves but the high plug & larger combustion chambers. Pretty good heads for a 327 up to about 350 HP, but if you find a set a Camaro guy might go nuts for them.

Nov 9th, 98, 7:52 PM
I know this is not the place for it,
But I have a set of non-accessory hole "fuelie" Heads currently on a 400 S/B in my daily driver.
The are cut for large dia springs, guides and Screw in studs and snap on seals. They are fitted with MAnley ProFlow Valves 2.02/1.60 3angle cut sitting in all new guides (replaced not knurled).
The heads are on an everyday use engine and are in excellent condition, But I need my accessory holes before spring for my A/C compressor.
Drilling them would be a sin, but may soon be a considered project.
Anyone knowing of someone in need of these "getting harder to find" heads, please email me, I'm looking to work a deal.


Nov 9th, 98, 9:23 PM
Tero, nope, I bought the 383 off of a friend in need just when he was finishing it up. Everything was new, including an Isky roller cam setup (Isky RR602, .602/300, 252@.050. Kind of radical, but desktop dyno says 520hp/450 lb/ft, over 400 from 3300-6000. That's with no porting. A friend tried the combo on Engine Analyzer software, came up 498hp/450lb/ft. He had a little trouble with putting in the cam specs, though. Got the whole package for $1800, and a lot of work on his 69 Firebird. He had over $4000 into it. Darren

Nov 11th, 98, 9:14 PM
This is getting good. Anybody out there know about these 041X castings? Bryan

Nov 12th, 98, 7:46 AM
I have a set of 292 "turbo" angle plug heads for about 12 years now. Ran them on 2 different motors with great power in the 11-12 sec range in the 1/4 mile. Casting date is 73 and only offered over the counter. They are beefier than most stock castings. I never measured the intake port volume but literature mentions around 170-175cc. I love these heads and would never part with them.

Nov 12th, 98, 6:41 PM
Allright guys,
I am about to make you all sick ! I just pulled out the receipt for my 292 angle plug heads that I purchased in Aug 1973. By the way I will cc the ports in the next day or two at the shop and post the results. The total price for both heads, stainless GM valves (2.02 x 1.60) Z-28 springs, valve seals and 2 head gaskets was $ 176.25 ! Boy do I wish I had bought a bunch of these ! Times like this make me glad I saved some of those old receipts. By the way, those heads on a basically stock LT1 short block went 12.50's in my 71 Chevelle 4 spd car so they do work.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Nov 12th, 98, 8:24 PM
Have any of you checked out the vortec head with 2.02 1.60 valves?A friend did a set for me and they run extremely good.The ports are big.I'll ask him tomorrow what cc they are.He told me that he saw where he could do some minor port work and these heads would make even more power.He has always did some great work with the old "fuelie" style heads.I wouldn't rule out these heads.I've had several sets of these older heads and they ran great but I'm going with the new heads with bolt holes because they will make some great power.
My .02 worth

Tero Toppila
Nov 23rd, 98, 6:15 AM
Hi Bryan! I suppose those #041x castings are just like the #186īs, i.e. very good original hi-po (camel hump / fuelie) heads.

The visual difference is that the #186 heads have got a small two-piece casting mark on the end of the head that looks like two halves of a ball beside each other, and the #041 has got some kind of a triangle casting mark. Sorry if that description was a bit akward, but I tried anyway...

The only bad thing is that those two castings have got shallow spring pockets that may be a problem if larger-than-original springs are installed. For example a roller cam usually needs very high spring pressures so outside diameter of the spring is also enlarged but the spring pockets are too small and cannot be machined very much on those #186 and #041x heads because there is a water channel too close.

BillK, you really made the greatest deal when you bought those angle plug #292īs back then! Iīm looking forward to hear how much those intake ports measure. By the way, you could also flow them on a flow bench......???

Nov 23rd, 98, 10:56 PM
Thanx, Tero! That spring pocket deal is definately some good info... I guess that rules out 1.550 springs!! They will probably see some use anyway, since I run cams between .500" and .535", and there are lots of hi-lift, stock dia. springs out there capable of that. Good hunting (head hunting, that is ) Bryan

Tero Toppila
Nov 25th, 98, 1:02 AM
Yes, you were right, Bryan. Those shallow spring pockets on those #041 and #186 heads generally rule out the 1.550" outside diameter springs. There are some smaller diameter springs and even some fancy conical shaped ones out there that can handle a lot of lift, but unfortunately they cannot provide enough spring pressure for those fast roller cam profiles.

I was talking with this old guy who is a long-time machinist and has got a lot of experience with small block Chevy heads and he told me that the water channel is more likely to be found if the spring pockets are enlarged both downwards AND sideways. The water channel cuts open on that part of the spring pocket which is the closest to the intake manifold side of the head. If the accident happens it may be fixed with some careful epoxy work or expensive cast iron welding, but you know itīs not worth the trouble or money. But if you just carefully machine the pockets only sideways and ONLY as much that the big spring just about fits there, you may succeed. But itīs a close call anyway, so youīre better off with other camel hump / fuelie castings.

By the way, on that wrecking yard where I found all those old fuelie heads there was also one pair of "too much" ported #186īs. The ports were enlarged so much that in the beginning of the intake port the pushrod holes were found, and in the middle of some intake ports the head bolt passages were cut open. Then there was a tube installed into the head bolt passage and everything was covered with epoxy! Not a pretty sight and I understand why those heads were there... ;)
But if somebody would like to try to port old fuelie heads those ruined ones could be very benefitical in shoving where the limits are, you know. Just to show a greedy grinder when to stop before doing the dsame mistakes as the other guy before.

I havenīt slept since you told us that youīre gonna measure your #292 angle plug castings, so have you got any results, yet..... ;)

Tero Toppila
Dec 15th, 98, 3:48 AM
Hi all

It seems that this "SB Chevy mystery head" topic is all done.

We got some valuable information about all fuelie / camel hump heads and some really interesting, too, particularly about #292 angle plug heads, and some about #461x castings, too.

BUT UNFORTUNATELY NO ACTUAL FACTS LIKE INTAKE PORT CCīS OR FLOW NUMBERS. We didnīt get the exact "hands-on tried and true" information from anybody, but a few close calls, anyway.

So when I did this trip from here Europe to there USA a couple of weeks ago I just went the easy way and bought World Productīs Dart II Sportsman heads, sorry ;) But my #291 small valve heads would have costed too much (from $590 to $880) to machine and upgrade, so I just didnīt see it worth the trouble. But if only had I better "mystery heads" to start with, it might have been a different story....

Anyway I will continue to keep my eyes open every time I come across some old hi-po heads like 292 angle plugs, just for nostalgiaīs sake ;) And by the way, in the future I am going to get both my small valve camel hump and those new Dart II big valve heads flowed on a flowbench. First in stock form and later pocket ported, but more on that later, couple of months or so.