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post #1 of 22 (permalink) Old Nov 2nd, 98, 6:25 PM Thread Starter
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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
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post #2 of 22 (permalink) Old Nov 2nd, 98, 8:49 PM
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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).]
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post #3 of 22 (permalink) Old Nov 2nd, 98, 9:13 PM Thread Starter
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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
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post #4 of 22 (permalink) Old Nov 2nd, 98, 9:54 PM
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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.

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post #5 of 22 (permalink) Old Nov 3rd, 98, 4:08 AM
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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.
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post #6 of 22 (permalink) Old Nov 3rd, 98, 8:18 AM
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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).]
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post #7 of 22 (permalink) Old Nov 4th, 98, 12:44 AM
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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!
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post #8 of 22 (permalink) Old Nov 7th, 98, 9:40 PM Thread Starter
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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
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post #9 of 22 (permalink) Old Nov 8th, 98, 12:22 AM
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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
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post #10 of 22 (permalink) Old Nov 8th, 98, 4:08 PM
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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.
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post #11 of 22 (permalink) Old Nov 9th, 98, 6:11 AM
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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....

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post #12 of 22 (permalink) Old Nov 9th, 98, 9:52 AM
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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.
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post #13 of 22 (permalink) Old Nov 9th, 98, 6:52 PM
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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.

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post #14 of 22 (permalink) Old Nov 9th, 98, 8:23 PM
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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
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post #15 of 22 (permalink) Old Nov 11th, 98, 8:14 PM Thread Starter
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This is getting good. Anybody out there know about these 041X castings? Bryan
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