Another head question for George!

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Nov 27, 2002 | 11:01 PM

LxMan1

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From: Louisville,Ky.

Another head question for George!

I was wrong about the set of heads that I have. They are C9VE A castings. What are they? These are what I want to put on my 77 460. They have studs and rockers on them. Do these require a different pushrod then the pedistal type that I have now?
Jimmy

Nov 28, 2002 | 09:17 AM

georgedavila

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From: Nevada

Another head question for George!

They're '69 heads with the smaller combustion chamber. On a '72 up block with stock pistons, they'll raise your c/r to about 9.5:1 and bolt right on. The early pushrod is longer than the pedestal pushrods as the pedestal heads dropped the valves .100 deeper into the head, so you'll need early pushrods. You'll like the c/r change.

Nov 28, 2002 | 01:02 PM

georgedavila

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From: Nevada

Another head question for George!

PS, get a set of Crane or other lock nuts, $20 or so, and you'll have an adjustable valve train that will allow you to adjust lifter preload.

Nov 29, 2002 | 12:58 AM

LxMan1

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From: Louisville,Ky.

Another head question for George!

Thank's George, you've been a great help. You sure seem to know your big blocks!
Jimmy

Dec 9, 2002 | 10:19 PM

LxMan1

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From: Louisville,Ky.

Another head question for George!

You have mentioned Rail type rockers. When you say this, I think of an FE motor or a Mopar. My 69 heads have studs and the 1/2 ball and nut( Similiar to a Ch%&! ) I Don't have any rails. I am also assuming that the pushrod slots in the heads are what keeps the rockers straight? Kinda like a guide plate?
Sorry to keep bothering you, This is the first Big Block Ford that I have messed with. I usually mess with 5.0's and 351C's. But I really love the pulling power of my 460, and it gets 1 MPG better than the 351W that I pulled out of it. Go figure, I guess it doesn't have to work so hard to pull the 4480lb truck around.
Do you have any documentation on the actual power increase just from changing the heads to reaise the compression from 8.0:1 to 9.5:1? I was just curious of what kind of power gains I might see.

Thanks again,
Jimmy

Dec 10, 2002 | 09:06 AM

georgedavila

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From: Nevada

Another head question for George!

'68-71 heads have the rail rockers. It's so named because of the rails on the rocker underside that guide the push rod, just like Chevy.

There's a formula for calculating hp increase by compression increase, but I can't remember what it is. Something like .3 hp for every point of c/r increase? Maybe someone else can remember the formula.

I ran a Desktop Dyno 460 simulation using the same engine @ 5000rpm:

8.0:1 - 438hp, 459tq
8.5:1 - 453hp, 475tq
9.0:1 - 466hp, 475tq
9.5:1 - 479hp, 503tq

You could back into those numbers for your application. To me, it looks like about a 10% increase. Pretty substantual.