Pushrod length for mechanical rockers??

I bough a 340 that is a pretty fresh rebuilt engine with mechanical camshaft and valvetrain.

It has the ductile iron adjustable rocker arms, with matching pushrods, etc.

While I was adjusting the valve lash prior to firing this engine up for first time (at least for me, since the folks who built it had run it a few miles on street and 3 passes down track), I noticed one of the rocker arms could not be lossened enouigh to obtain the desired valve lash. The cup at top of pushrod was hitting the rocker arm when the adjuster was loosened all of the way.

Upon further inspection i found the pushrods were all of the same lengthand a few of them were hitting on the bottom of the rocker arms at two locations.

I swithced a few rockers around so they all now adjust out properly.

I read my Mopar Performance "A"-Engine book and they recommend making custom length pushrods with the mechanical rocker arms to maintain proper valvetrain geometry.

Has anyone here any experience with this??

The old mopar book lists P5249815 as the part number for the custom length pushrod kit, has anyone bought a set lately or know where I can buy a set???

Thanks,

Bob