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-   -   1967 #061 valves vs 1971 #96. (https://forums.maxperformanceinc.com/forums/showthread.php?t=871521)

S.F. 01-23-2024 10:39 AM

1967 #061 valves vs 1971 #96.
 
Hello!

Is the length different betwen 1967 #061 valves vs 1971 #96?

Can I use the same Crower 404 springs?

The valves are OEM not change.

Is there a better spring for #061 heads with 041 camshaft and 1:65 rockers?

How about pushrods?

Planning on rebuild my 455" with #061 heads.

This combination worked for 7 years until I with no experiance
Raised the ignition and the cast pistons fell apart.

I know that this is not what most people does with this much compression.

But it worked for me 7 years and the engine was wery strong and low
fuelconsumtion.

Thank You from S.F. in Sweden.

John Milner 01-23-2024 11:05 AM

The length should be different between those two heads. The 061 heads should have around a 5.08" length valve and the 96 heads should have around a 4.98" length valve. The 4.98" valves will be too short for the 061 heads. The 4.98" valves would likely cause a coil bind situation in the 061 heads when used with the Crower 68404 springs unless someone got creative with the keepers and retainers or machined the spring pad down.

S.F. 01-23-2024 11:52 AM

Thank You!

I will machine the heads after meassure.

From S.F. in Sweden

steve25 01-23-2024 12:09 PM

The Chambers in the 061 heads are terribly detonation prone that’s why they where only made for and used for 1/2 of a years production.
I hope you are not planing on running them unless your forced to for originality reasons.

S.F. 01-23-2024 01:11 PM

My cam for this heads was custom grinded for the combination in the 80;s.

The engine was 455 +060", cast piston, OEM deckhight.

Workt very good for 7 years.

The cam has 299/310 advertised duration and under 0.375" lift.

Looks like a regrind RA3 similar to rollers on the veery flat top.

Assymetric in and out.

Maby this cam is better then 041 on my combination.

Heads not ported, pressed in studs (I will change to screw in ARP).

OEM cast exhaust manifold, 2.5" pipes.

OEM intake.

3.08 gears and TH400 with no kick down.

Disturbur 12 initsial, 24 max no vacum.

My engine now is 455 +040".

Do not need to use this, my engine works very well.

Just want to see if it can be done again.

The engine was very strong and low on fuel.

I know that the compression is sky high and I have not seen any
build like this.

But it worked very well for 7 years untill I screw it upp with more ignition.


If I build this I will let You know how long before the engine collaps.

And I know that this is something not to do.

But it has been done before.

Thank You from S.F. in Sweden.

steve25 01-23-2024 01:47 PM

With the cylinder pressure your going to have at .060” over with those heads I would run the 041 cam if you have it.


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