Pushrod Length Ordering

I mocked up a hydraulic lifter with some washers to make it solid to check for pushrod length. I am coming up with 6.800.

Now, I know that anywhere from 1/2 turn to 2 1/2 turns preload have been suggested through my research for the Magnum lifters.

My question is, whichever preload I choose, do I just add that much length to my 6.800?

Say I were to choose 2 turns preload (3/8 stud...... .042" per turn") I would shoot for a 6.900 pushrod?

1 turn would be 6.850 etc...

And just to avoid confusion with previous statements, I have 5/16x3/8 stud adapters to run 1.6 roller rockers so that's why my math is what it is.

Thanks and hope y'all have a great weekend!
Seems mostly correct to me, but wouldn't it be 6.858" (One turn=.042")