It means that those were the heads to have back in the day, now the Vortecs with smaller valves run circles around them.

 

It means that those were the heads to have back in the day....

Yup. Also known as "Fuelie" heads, FWIW.

Chris

***EDIT: "3782461....64-66...327......Camel hump,no accessory holes,160/62cc port volumes,62cc chamber" (As per Mortec)

 

Fwiw, camel humps or double-humps were the very first of the large intake ported stock high performance small block heads way back about 1961.

They first came out IF I have this right(??) on the 1961 315hp FI/283 as -461X medium valve heads!

Next, they then came out on the 1964 365 carb'ed and 375hp FI/327s as -461 large valve heads!

Thus the nick-name "fuelie" heads came about.

The -461X heads have about 170 cc intake ports whereas the -461's only have 160 cc intake ports. BUT the x's are rare as hen's teeth nowadays b/c all the racers used them..

pdq67

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I think I heard/read somewhere the true fuelie heads were the ones with the factory 2.02/1.60 valves as opposed to the ones with just 1.94/1.50 valves.

 

Both valve sizes were used in FI.

 

And the 2.02 valves were used on the L79, L76 and LT1 (which were not fuel injected).

 

Right..

I was talking about the early -461 heads is all.

And not the later -462, -186, -291 or -041 big valve heads used on the newer stuff.

And the only "double-quench" head out there except for the old -461 is the -601 type head if I recall right..

And I'm not going to get into the "sparkplug trough" -306 type head that came out back when the SB was first out..

Try this site to see pic's of some of these heads..

http://www.chevytech.net/

pdq67

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The VERY, VERY, VERY first heads with the double humps, as already mentioned, were introduced in 1961 on the 315hp/283 with Fuel Injection. Those heads were ONLY on the 61 FI engine (thus the origin of the term "Fuelie heads") and they had 1.94/1.5 valves and also as mentioned, they were the 461 (and 461X) castings. These heads continued up through 63 on the 300, 340 and 360hp 327 engines and all of them ONLY had the 1.94/1.5 valves. THEN, in 1964, these same heads came with either 1.94/1.5 or 2.02/1.6 valves, depending on which engine they were to be installed on. The 300hp/327 got the smaller valves and the 365 and 375hp 327s got the bigger valves. The 350hp/327 didn't come out until 1965 and for all practical purposes it was the same engine as the 365hp version, except, it had a hyd cam. The 62-3 340 and 360hp versions had the original "Duntov" solid cam (which first cam on the 57 270hp 2x4 and 283hp FI engines) and then the 64-5 365 and 375hp versions got the 30-30 cam. So, BASICALLY, the 340hp version of 62-3 and the 365hp version of 64-5 were the same engine except for the bigger valves and bigger cam. And the same goes for the 360hp of 62-3 and the 375hp version of 64-5. The lone difference is the 350hp (L-79 as many refer to it) version which continued up through 68.
A solid lifter small block did not return again until the 67-69 302 Z28, and then the 70-72 LT-1/Z28. The 70-72 LT-1 and Z28 engines were identical. The LT-1 in the Vette was rated at 10hp more than the Z28 version supposedly because the exhaust system of the Vette was more efficient than that of the Camaro.

Now, this brings me to a question. Why did the 350hp/327 become so very well known as the L79, but yet VERY FEW people know that the 375hp FI engine is the L84? Its strange how the RPO number for some engines stuck, but yet it didn't for others. Another example, NO BODY calls a 65 Chevelle with a 396 an SS396, virutally everyone calls it a Z16. Same thing with the alum headed 427 of 67-69 and the 69 solid alum 427. Everyone refers to them as the L88 and ZL1. Like I say, the RPO sticks for some, and not for others!

 

Right..

I was talking about the early -461 heads is all.

And not the later -462, -186, -291 or -041 big valve heads used on the newer stuff.Not to mention the -492

pdq67

 

Funny how we're talking camel hump heads.....a friend of mine calls me tonight and says a guy he works with is selling a set, complete, and to make an offer. Hhhmmm.....knowing they're no longer the hottest thing on this earth what would you offer?

 

Great info as always guys! Can I jump in and ask where exactly is the X at on those 461 type of heads? Some have said it was after the cast #- I have also heard the X is on the under side- can someone clear that up for some of us? Also, exactly what years were the 461X heads produced? Thanks, Dan

 

The X is after the casting number, also on the deck side of the head it will have the '461X' in various places.