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440 Head gaskets and others

Unknown thick black gasket. Similar to 1009 results.

20251129_095019.jpg
 
A word of caution if the rockers are the unbushed Comp Pro-Magnums.
They had a history of galling/seizing on the shaft if the springs were near/over 350lbs open.
Since you’re taking it apart anyway, now is the time to pull all that stuff apart and inspect for unhappiness.

The dyno info looks like it’s from Desktop Dyno 2000.
Fwiw, there have been a couple of similarly built 440’s dynoed here using that same cam.
They ran great, but made noticeably less power than what’s on that sheet.

But, to answer the first question…….. I use the FP 8519’s on that type of build.
 
A word of caution if the rockers are the unbushed Comp Pro-Magnums.
They had a history of galling/seizing on the shaft if the springs were near/over 350lbs open.
Since you’re taking it apart anyway, now is the time to pull all that stuff apart and inspect for unhappiness.

The dyno info looks like it’s from Desktop Dyno 2000.
Fwiw, there have been a couple of similarly built 440’s dynoed here using that same cam.
They ran great, but made noticeably less power than what’s on that sheet.

But, to answer the first question…….. I use the FP 8519’s on that type of build.
Is there a reason you wouldn't choose the 1009? Cost?
 
A word of caution if the rockers are the unbushed Comp Pro-Magnums.
They had a history of galling/seizing on the shaft if the springs were near/over 350lbs open.
Since you’re taking it apart anyway, now is the time to pull all that stuff apart and inspect for unhappiness.

The dyno info looks like it’s from Desktop Dyno 2000.
Fwiw, there have been a couple of similarly built 440’s dynoed here using that same cam.
They ran great, but made noticeably less power than what’s on that sheet.

But, to answer the first question…….. I use the FP 8519’s on that type of build.
I will for sure be doing a close inspection on the heads when I have them off. Thanks for the heads up.
 
Is there a reason you wouldn't choose the 1009? Cost?
Post #20.

I’ve had first hand experience of the 1009 gasket hanging on the edge of the bore and the fire ring getting squeezed over the edge, allowing the combustion gasses to get past the fire ring and torch the gasket.
So, I just won’t use them any longer on a 440 or 400 block.
Later model blocks with the big chamfer at the top of the bore are especially susceptible to this.

If it’s an application where I feel the 8519 isn’t up to the job……it gets Cometics.
 
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A word of caution if the rockers are the unbushed Comp Pro-Magnums.
They had a history of galling/seizing on the shaft if the springs were near/over 350lbs open.
Since you’re taking it apart anyway, now is the time to pull all that stuff apart and inspect for unhappiness.

The dyno info looks like it’s from Desktop Dyno 2000.
Fwiw, there have been a couple of similarly built 440’s dynoed here using that same cam.
They ran great, but made noticeably less power than what’s on that sheet.

But, to answer the first question…….. I use the FP 8519’s on that type of build.
What kind of power numbers did you see with that cam? I was thinking that Desktop Dyno might be 100 horsepower optimistic at 542.
 
Post #20.

I’ve had first hand experience of the 1009 gasket hanging on the edge of the bore and the fire ring getting squeezed over the edge, allowing the combustion gasses to get past the fire ring and torch the gasket.
So, I just won’t use them any longer on a 440 or 400 block.
Later model blocks with the big chamfer at the top of the bore are especially susceptible to this.

If it’s an application where I feel the 8519 isn’t up to the job……it’s gets Cometics.
Ok thank you. Yes I've torched one on a 4.31 bore. Mainly run cometics now.
 
What kind of power numbers did you see with that cam? I was thinking that Desktop Dyno might be 100 horsepower optimistic at 542.

One engine got ootb Stealths(with a spring upgrade) and a SD manifold.
It was tested with the shop Holley 700dp(sniper in the car) and 1-7/8” headers.
Made right about 515tq/470hp.

The other one got ootb TF240’s and a Torker II, not sure what carb, same 1-7/8” headers.
Not much of a gain over the other engine…….about 525tq/480hp.

To put those #’s in perspective, another similar build but with 10* more cam, rpm heads that got the seats done and bowl blended, SD intake and an 850dp, same 1-7/8 headers.
That one made like 540tq/515hp.
 
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