461 and 462 heads. What is different?
08-06-2018, 08:56 AM
#81
Le Mans Master
What’s the answer?
My 66, L-79 , built 4/07/66....should have 461 or 462. John Z indicated 461...
So what is true?
Jack
So what is true?
Jack
08-06-2018, 09:34 AM
#82
I can't answer your question except to say that my 67 corvette (built 9-22-66) has 462 heads. I don't believe there is a big difference between them except what's mentioned above somewhere about the spark plug quench area.
08-06-2018, 09:36 AM
#83
Melting Slicks
I can tell you for a fact that the 461X head was used on the 1963 Flint 300hp engines, corvette or impala, I have the complete engine in my garage out of a Impala and it's EXACTLY the same as corvette down to the 3460 Carter afb carburetor. This is a early engine dated October 1962.
Rich
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Jackfit (08-06-2018)
08-06-2018, 10:15 AM
#84
Safety Car
First off I'm am not an authority on Corvettes. Back in the 70s I worked for a shop that built NHRA super stock heads and lots of them. We were constantly buying head cores. As stated here the X head had about 5 more CCs intake runner volume. The 461/462s were identical other than the relief in the chamber on the spark plug side for the 462 and the spark plug location. There is another casting as well the 291 and it is the same as the 462. I can say we bought a lot of X heads before anyone caught on that they were different. They were rare but I believe too plentiful to have only been on fulie Vettes. I don't ever remember seeing a set come in as cores purchased from the scrap guys that had big valves or screw in studs. At one point I was told the X referred to the foundry that cast the head. That is only here say with nothing to back it up. Just for reference at first we paid $10 each for head castings and as they grew harder to find they went all the way up to $15.
08-06-2018, 10:35 AM
#85
Race Director
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461X heads were first installed on the 275 and 315 HP '61 FI engines. That's how they got the name "fuel injection heads". Their use spread to 340 HP engines in '62 and ALL 300 HP engines installed in both Corvettes and full size passenger cars, and this usage continued through '63, so back in the day they were fairly common. All were built by Chevrolet with 1.94/1.50" valves and pressed rocker studs.
A buddy who was familiar with sprint car racing back in the seventies said that many engine builders preferred 461X castings because the cast iron alloy had higher nickel content than later castings, which made the 461X castings tougher and more resistance to cracking. This was after Chevrolet released the various "off road" heads. I know when I pocket ported mine back in the seventies it was a very time consuming process. That iron was tough!
Duke
A buddy who was familiar with sprint car racing back in the seventies said that many engine builders preferred 461X castings because the cast iron alloy had higher nickel content than later castings, which made the 461X castings tougher and more resistance to cracking. This was after Chevrolet released the various "off road" heads. I know when I pocket ported mine back in the seventies it was a very time consuming process. That iron was tough!
Duke
08-06-2018, 12:49 PM
#86
Drifting
My Jul 13 '66 build date base 327/300 engine has 462 heads; both are dated F186 (Jun 18 '66). Engine ***'y was Jun 27.
Jeff
Last edited by vark_wso; 08-06-2018 at 01:01 PM. Reason: Clarity
08-06-2018, 01:12 PM
#87
Le Mans Master
had cracks. My 461’s are dated Nov - Dec 1965. I do have the 2.02 valves.
Jack
Last edited by Jackfit; 08-06-2018 at 01:15 PM.
08-06-2018, 02:06 PM
#88
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St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21-'22-'23-'24
So a n00b pours gas on a 9 year old thread, and the fire blazes right back up again! 
So now I gotta go back and read 80+ posts so I can learn something.
So now I gotta go back and read 80+ posts so I can learn something.
Last edited by Railroadman; 08-06-2018 at 02:07 PM.
08-06-2018, 02:38 PM
#89
Le Mans Master
Last edited by Jackfit; 08-06-2018 at 02:41 PM.
08-06-2018, 02:42 PM
#90
Le Mans Master
Portland ME Harbor yesterday
08-07-2018, 06:22 PM
#91
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St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21-'22-'23-'24
08-31-2020, 05:20 AM
#92
1st Gear
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If any1 wants to see them, I have two 3782461 heads with the diff cambers. I got the 327 out of a 65 the got t-boned. He only had a little under 12,000 on the motor. took them to mach shop to have them fluxed and cleaned up. of course he didn't bother to tell me the cambers were diff until after he was done with them. Last time I went to him. What I didn't notice until I was really bored one nite, is on the bottom side where it has just the last 3 numbers in the cast is, 1 has the 461 and the other has a 462 ! But on the top castings they both have the same 3782641? Anyway I know this is an old thread and this is 1st time on here, I have the pic's. The heads have been crated up for the last few years so they d be ready to go when i sell them nailed,screwed an glued. If they weren't id take some better pic's. but i have next to each other so u can see the diff. Let me know.
08-31-2020, 07:01 AM
#93
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10 year old thread will not die.
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mike coletta (08-31-2020)
