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Old 08-10-2024, 12:16 PM   #1
Detour
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Should I change heads?

The truck is a 67' K20 that supposedly came with a 327 factory. However, the current block dates it most likely to a 64' Impala with a hodge lodge of years/models for parts. The heads are the pyramid onto of a rectangle, that the internet says are 9.25:1 59cc chambers and 1.72/1.50 valves.

The truck will only be used for camping and Home Depot runs... once in a blue moon to tow a 2 horse trailer. So I don't care about maximum power, but I do like tinkering and a extra power is fun to play with.

So the question. I hear a lot about camel hump heads and the like and was wondering if they would be worth swapping to. Looks like they flow better, but have 62cc chambers which would lower the compression and might hurt low end torque.

Other info. Quadrajet, 1968 corvette factory manifold, 2.5" single exhaust, current cam is a mystery, but thinking about a mild upgrade in the future.

Last edited by Detour; 08-10-2024 at 09:58 PM.
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Old 08-10-2024, 12:27 PM   #2
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Re: Should I change heads?

I would retain what you have if the only option was the camel hump heads.
If I changed heads it would be to the Vortec heads. They have stellite valve and hardened seats plus flow a bunch better than the antique camel hump heads.
The also require center bolt valve covers that don't leak and a different intake.
It will increase power over what you have.
I can see no reason to run the old heads unless you are restoring a truck.
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Old 08-10-2024, 10:44 PM   #3
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Re: Should I change heads?

I have seen good things about the Vortec heads over the years but I want to keep the old manifold style with the front oil fill tube. Opinion on that might change in the future. Thanks for the info.
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Old 08-11-2024, 08:41 AM   #4
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Re: Should I change heads?

What’s the casting numbers on the block and heads?
And what numbers/letters are on the pad in front of the passenger side head?
You need to confirm what you have first.
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Old 08-11-2024, 08:07 PM   #5
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Re: Should I change heads?

Zero benefit to that change; keep your money.

"Camel hump" (462/487) heads were the best of their time, but even a stock Vortec flows more with a better chamber. And with any head swap, you gotta match the cam.

Vortec chambers are 64cc, so you'd be losing about 1/2 point of compression...also not a good thing.

A machine shop could drill, bore and ream a hole for the filler if you gotta have it.

Better places to spend money - small-tube headers, mild cam swap, cheap intake, etc.

Head swaps are never as easy you might think...
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Old 08-13-2024, 09:48 AM   #6
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Re: Should I change heads?

Attachment 2384903
Quote:
Originally Posted by geezer#99 View Post
What’s the casting numbers on the block and heads?
And what numbers/letters are on the pad in front of the passenger side head?
You need to confirm what you have first.
Here is a picture of the pad, I was not able to find reference to this casting when I looked last year. The numbers on the back of the block are 3858180
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Old 08-13-2024, 04:09 PM   #7
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Re: Should I change heads?

"S" suffix code comes back as a 1962 327 in a "full size" car with a Powerglide

But the Casting number shows a 64-67 327 with 250-300 hp

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Old 08-13-2024, 06:08 PM   #8
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Re: Should I change heads?

Before you go buying heads you should tear the motor down to see what pistons are in it. Check how far the pistons are down in the cylinder. That info will help decide head type and head gasket thickness.
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Old 08-13-2024, 07:18 PM   #9
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Re: Should I change heads?

Camel humps are old as hell, outdated and honestly don't flow that well stock.
For the purchase price and the need to likely do work to them, you could buy some cheap aftermarket heads for barely anything more.
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Old 08-15-2024, 01:27 PM   #10
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Re: Should I change heads?

Leave the heads unless or untill you plan to upgrade the whole engine.

You'll loose mpg due to lower compression. Along with part throttle or tip in hp/tq.

If you replace the heads you will likely gain less then 25hp unless. Your cam already flows enough to tax the heads, or you plan the upgrade at the same time.

Last time I check Vortec heads were $700 delivered new. So You'll need a manifold, rockers, and a possibility of push rods. So depending on how you get the parts, and rebuilding. You could be $700 to $1200 deep into less then 25 hp.

Well of your buying or rebuilding heads make sure you get them upgraded for high lift cams with Bee hive springs, seat mods or both.

Me personally. I would build a either a 95+ Vortec or 92+ Gen 2 LT1 for ease of conversion with distributors, and carbs. My LT1 tows 5000 pounds easily, hauls 1500 pounds like it's not there, and runs 87 octane easily with 10-1 compression.
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Old 08-15-2024, 02:35 PM   #11
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Re: Should I change heads?

Quote:
Originally Posted by Detour View Post
Attachment 2384903

Here is a picture of the pad, I was not able to find reference to this casting when I looked last year. The numbers on the back of the block are 3858180

Those are 283 powerpack heads, small valves

If it works , dont fix it. Those heads will give you low end power
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Last edited by GSP7; 08-15-2024 at 04:18 PM.
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