tryin t think, long ago--mushroom clutch end is bigger than pushrod Firko & has a 5/16 ball between it & pushrod. Not sure of pushrod length but diameter is 1/4 by memory [6.5mm] & is a reasonable fit through the shaft so it sits pretty good against the 5/16 ball as it operates the clutch. In saying that--there's a 1/4 ball recessed into the lifter arm which sometimes gets out [on the bench] if the little punch marks wear off. for length i [if stuck for genuine bits like me] just fit it all up with a longer rod than necessary, sit lifter cover against it & measure the hap to shorten up & re-harden the end. I do a similar measuring trick when making throttle cables--solder end on lightly, fit it up, pull outer cable to seat everything, then measure the gap to the adjuster or carb top bit.
That should start the ball rolling & if my memory's up the creek hope someone puts me right. Cheers.
