1.5 or 1.6 roller rockers.

1967formulaS said
I have. 0.022 clearance between rocker arm body and the retainer. Is this not enough?

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You need clearance throughout the lift cycle. I rounded the nose a little. correct valve stem height is critical.
you need to get the geometry as close as possible. no more than 2.5 threads showing on adjuster and pushrod should be aligned