440 Six Pack pushrods travel into hydraulic lifter

Posted By: PJSIXPACK

440 Six Pack pushrods travel into hydraulic lifter - 03/26/12 07:27 PM

Is there a simple way to measure pushrod travel into a hydraulic lifter on 69 440? I am going to use my stock 69 1/2 heads but the block has been decked and I want to make sure that the pushrods don't bottom out. I have Six Pack rocker arms and pushrods so the deck heighth of the block is the only variation from stock. I am purchasing a shim kit for the rocker arm shafts so that I can equalize the travel into each lifter.

Thank you in advance.

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Posted By: JohnRR

Re: 440 Six Pack pushrods travel into hydraulic lifter - 03/26/12 09:41 PM

Quote:

I am purchasing a shim kit for the rocker arm shafts so that I can equalize the travel into each lifter. Thank you in advance.

I don't think you'll be able to accomplish that since you would have to put the same amount of shim under each pedestal.

Adjustable pushrods or rockers is the answer. I did a 440 with smith bros. adjustable pushrods , pricey but I was able to set the same preload on every lifters basically the same .

Posted By: HPMike

Re: 440 Six Pack pushrods travel into hydraulic lifter - 03/26/12 09:47 PM

Quote:

Quote:

I am purchasing a shim kit for the rocker arm shafts so that I can equalize the travel into each lifter. Thank you in advance.

I don't think you'll be able to accomplish that since you would have to put the same amount of shim under each pedestal.

Adjustable pushrods or rockers is the answer. I did a 440 with smith bros. adjustable pushrods , pricey but I was able to set the same preload on every lifters basically the same .

...Or he can use all the stock stuff if the valve stem tips are fairly the same height, then he can use an adjustable pushrod to get the lash out, Measure the length of that pushrod, add 020-050 and hed be good to go.

Just make sure you check both banks to make sure that there isnt any variation. There shouldnt be that much, but always good to check. Im not a fan of using any rocker shaft shims. Always seemed like a cheesy way out of a solvable issue.

Companies like Comp Cams and Trend stock entry level type PR's in a myriad of lengths that you should find what you need without bearing the expense of a "custom" pushrod.

MB

Posted By: lewtot184

Re: 440 Six Pack pushrods travel into hydraulic lifter - 03/26/12 11:58 PM

get a checking push rod, extend it to where there is zero lash and measure the length. add whatever preload you want to the checking push rod length and thats what you want for overall push rod length. adjustable push rods can be made whatever length you want or buy a custom length. big block chevy exhaust push rods are about .060 shorter than stock and could be an easy fix.

Posted By: MLR426

Re: 440 Six Pack pushrods travel into hydraulic lifter - 03/27/12 02:32 PM

69 1/2 heads ?? They are no different then any other 906 head.
How much was the block decked ? Are you using a .039 fel-pro gasket to replace the .020 head gasket steel shim ? Is the heads still around .990 after milling to flatten ? You may not need anything. I would suggest adjustable rockers if you have to do something to readjust the pre-load that way you can really lighten the load if need be and know what you have after your done.

logan426