rockers help

Off the shelf pushrods for hydraulic flat tappet cams with adjustable rocker arms have a length of 7.33 inches and these are available from comp, crane and others. I agree with the previous post. You want to add 1.6's to get a little more out of the engine. Measuring the correct pushrods length for your specific engine setup of heads, deck height, ... will help ensure you get the most from your investment and minimize the chance of lifter pump up. Off the shelf will likely be fine. Check all clearances as discussed above and if the intake is off you can measure lifter preload or clearance from the plunger to the snap ring when the lifter is on the cams base circle. You do not want the clearance to be too large. Usually around 0.025 is fine.