[charlie66]

Originally Posted by blaktopr

You will have to work at getting 3/8 in there. Since you need guide plates, you have to modify them or use a sbc type. Its not about the size of the hole to the size of the pushrod. Its about where the pushrod travels through the range of the lift based on the rocker. As the rocker goes from closed to open, the pushrod will travel back and forth. Depending on the ratio of the rocker, the pushrod can rest at different positions of the pushrod hole. The higher the ratio, the closer to the rocker. You have to mock up the setup on a block and start taking out material until it doesn't bind. You may even get thin on the pushrod wall/port side and adding a sleeve may mess with the area at that part of the port. You can't run a tapered pushrod with a guideplate. And others here are running shaft rockers so they don't need guideplates and can run any size they can make fit.

I'm shooting for 7/16..