Pushrod length tool came with NO instructions!

[Kern Dog]

I really hate it that these parts companies do not include instructions with non stock aftermarket parts!
The rocker arm kit I got from Mancini came with no instructions. Same with the tool for checking the pushrod length.
I'm not an idiot, but there should at least be some rudimentary guidelines.  The tool has 8.8 to 9.8 printed on it for the working length, then some white dashed lines. NO numbers. Yeah... THAT would be too easy, right?
So my question to you all is this: How do you measure, or more accurately, from WHERE do you measure the push rod?
Bolt rocker shafts to heads. Torque to spec. Unwind PR tool until zero lash is achieved. remove tool and measure. Measure where?
The tool is ball on the lifter end and cup on the rocker arm end. My concern is that if the various push rod companies have different type cup ends (Some deeper, some wider) wouldn't it be inaccurate to just measure the tool from end to end? Isn't the critical number the point between the lifter and the adjustment screw end of the rocker arm?

[c00nhunterjoe]

You actually answered most of your own questions. You need to call whatever company pushrods you are gojng to use and ask them how they measure them. Rocker nuts should be 1-2 threads showing into the tool.

[Kern Dog]

I agree....

[68CoronetRT]

I just went through all this. Here is the quick and easy answer.

Effective length is the length from the bottom of the cup to the end of the ball. Smith brothers will ask you for that dimension.
Overall length is from top of cup to end of ball.

Its pretty easy. Get a micrometer that goes to 10" and adjust your pushrod up for your pre load with the correct rocker arm geometry all setup. Then measure the cup depth. Most likely it will be .150 or roughly 3/16". Measure your overall length and subtract that ball depth and that gives you your effective length.

Then decide if you want 5/16 or 3/8 ball end. I went 3/8 ball end with a 5/16 .088 wall pushrod, 4130.

My only problem I ran across is my adjustment tool was a little shallower than the pushrods I ordered and my effective length got a little messed up. This is my fault for not paying closer attention to the depth of the cups. But since I ran my geometry right in the middle I had plenty of room for movement, so they will work fine.

You should be fine!

[b5blue]

Dig around here :  http://www.pushrods.net/
  These guys are A number 1