Tick Tick goes the magnum.

RustyRatRod said
Can you describe in depth how you measured? Here's how I do it. I order a pushrod checker straight from "whomever" I plan to buy pushrods from. Done this before with Smith Brothers, so lets say them. I get the checker. Get the camshaft lobes on the base circle. Now adjust the checker to take all the slack up, plus "however much" preload I think will work best for a given situation. I prefer a light touch with preload so I normally go .025"-.040" after all the "up and down" slop is taken out. Then, I send the pushrod checker back to Smith Brothers telling them "I need X number of these".

thanks for the reply, so i installed the the pushrod checker until there was no slack, rotated the engine a couple times by hand after marked the top of the valve tip, trying to get the pattern in the middle then measured it. ordered the push rods, although i did not account the preload, so how would i account for this, so if i get a measurement of 6.945 accounting for preload i should go 0.25-0.40 longer so in the 6.975 range? these are magnum stock roller lifters and stock rockers 1.6