What length pushrods you using? Rockers? Locknuts or stock?
Could be the wrong rocker geometry, improper studs for the rockers or the nuts bottoming out prior to proper valvetrain adj. Which leads back to geometry.
Which heads?
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
