Ok so how do i use one? My block is decked.. I have cly 1 at TDC comp stroke, dist at no1.? stock type rockers and shafts, hyd comp cam

Bolt rockers on w/ pushrod installed.

Adjust rocker w/ around 1 1/2 threads sticking out the bottom.

Unscrew length checker until it fits and mark it or lock it down.

Disassemble and measure checker accurately.

Allow for Hydraulic lifter Preload?

ok, i am using stamped steel rockes.. like the oem

so i just want to adj checker till there is no play between rocker and valve, then lock it down? I though i had to do approx 1/8 turn after?

IIRC the preload on a factory hydraulic should be .020

Due to manufacturing tolerances, stem height etc. you really should do each one seperately to get it right. If measured seperately, I believe you could get by w/ less preload, maybe .015 or so.

Now might be the time for a set of adjustable rockers, it would save a lot of headaches.

I have cheapo adj rockers, the adjs broke.. not heat treated i suppose.. but i want to get rid of them.. dont trust them, Now i want to go with something easy and reliable..and the factory type rockers work for me.. but i dont want to just throw stock legnth push rods in it.. the block has been decked not sure how much..the heads 70-72cc and are not milled and the head gasket is .039 thick..fel-pro i believe..

the other thing to check for and keep an eye on...at least with adjustable rockers, is that you're keeping the tip of the rocker over the center of the valve, or slightly to the outside, so that as the rocker cycles, it sweeps across the tip of the valve stem without ending up on the retainer or right on the edge of the stem.

that's what's known as 'proper geometry'

but with factory non-adjustables (assuming you're using a fully pumped up or solid checker lifter) lock it down when you hit "zero lash" remove it, measure it, add .020 -.030 or whatever preload you want to run.

I made a checker lifter for both measuring proper pushrod length, and for degreeing in a cam. I removed the innards of the hydraulic lifter and replaced them with solid spacer, then put the top cup back into position.

lots of suggestions, but use the KISS method first and always...
How much lifter pre-load do you have with the stock push rods? Probably be just fine with those.. .020-.040 should be spec... What does your lifter manufactor reccomend?

found this on the comp site

Setting Hydraulic Lifter Pre-load (Adjustable Valve Train)

When installing a hydraulic cam, lifters or rocker arms, establishing the correct lifter pre-load improves both performance and engine life. Insufficient pre-load will create excessive valve train noise and wear. Excessive pre-load will cause rough idling and low manifold vacuum, and can even lead to severe engine damage. With an adjustable valve train, proceed as follows:

Install the pushrods and rocker arms. Be sure the pushrods are seated correctly in the lifter and rocker arm. Turn the engine over in the direction of rotation until the EXHAUST pushrod just begins to move upward, opening the valve. Now adjust the INTAKE rocker of that cylinder. Carefully tighten the nut on the intake rocker while spinning the pushrod with your fingertips. You will feel a slight resistance in the pushrod when you have taken up all of the clearance. This is “zero lash.” Turn the adjusting nut to the specified pre-load – typically 1/4-3/4 of a turn, but this will vary based on the lifter number.

Turn the engine in its rotation direction until the intake pushrod comes all the way up and almost all the way back down. Now set the EXHAUST rocker to “zero lash” and add the specified pre-load. Repeat this process for all remaining cylinders.

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Setting Hydraulic Lifter Pre-load (Non-Adjustable Valve Train)

COMP Cams® recommends using an adjustable pushrod to check the pre-load. Typically, only one cylinder needs to be checked in this process. After applying lube, install the adjustable pushrods and assemble the valve train. Using the same procedure mentioned earlier, adjust the intake and exhaust valves to zero lash by changing the length of the adjustable pushrod for precise fitment. Order a pushrod that is .020"-.070" longer than the pushrod length at zero lash to ensure the proper pre-load.

well used the checker, i adjusted it till it started to move the lifter and touched the rocker.. i pulled it out and compared it with a stock PR, wow approx half the ball shorter then the stock PR.. ill run it to a shop that can mic the adj PR.. comp cams say 20-70 on preload..I also seen up to 120 preload would be good.. I would try the stockers but affraid it might damage things..the intake is also on so that makes it a bit harder, but with a boro scope i can see my lifters move as i tighten up my checker.

I like to set the preload on hydraulic lifters with the intake pan off so I can use a .015 to .020 wire as a go no go gauge I do use adjustable rockers now, I use to use adjustable pushrods on all eight cylinders,they are a pain in the rear to set, you have to have three 3/8 open end wrenches to set and lock them That was a long time ago when adjustable pushrods where the only solution for many motors I have one set in stock, not sure if they are low decks or high decks See how long you need, maybe I can help you out with a adjustable set