[BB427]

If you have a pushrod you can sacrifice,cut it and tap it on the inside and thread the two halves together with an all thread and two jam nuts, you now have a tool to use. You want the roller of the rocker arm in the center of the valve tip @ 1/2 lift. Measure the overall length and see if any manufacturer makes this length. If you need to order custom length Manton makes a nice custom pushrod.