This is typically an issue with the small block Chevy, Ford and Mopar engines.
When a large diameter spring is used with a “low“ ratio rocker arm, it can create a clearance issue between the pushrod and the cylinder head. The large spring requires a longer rocker to keep proper clearances. The longer rocker requires the adjuster to be further away from the fulcrum, increasing the overall length of the rocker even more.
Some people machine the rocker arm for clearance, but this is NOT anything we recommend. The area of the rocker that makes contact with the