Hydraulic lifter/rocker arm adjustment

[J-440]

  I know the basic how-to on when to adjust the intake rocker just when the exhaust rocker starts to open.  I spin the pushrod and tighten the allen head and then tighten some more when I can barely spin the pushrod.  Here's the deal: the adjuster nut needs to be tightened half-turn then your done.  My nut will only tighten to about 1/4 turn.  I cut these pushrods myself, triple checked the length and still can only manage a 1/4 turn.  What's the deal?  .600 lift springs on INDY EZ-1 heads with Hughes blue roller rockers are what I'm dealing with.

Thanks again.