T56 Input shaft end play

[88foxbod]

My TOB recently spun itself to death so I decided to make the swap to the newer style Liberty 26 spline input shaft. I've read up on alot of the posts about checking endplay.
The stock shim was .040, so I tried that out first and got ZERO movement. So to avoid it being too tight I went down a few sizes.... I did this about 7 times and finally got down to my smallest shim at .029 and still NOTHING.
The only time I get indication of movement is if I pull out and wiggle the input shaft a little, otherwise there is no in/out movement.
Has anyone else used that small of a shim? If I throw in a .034 shim, pull and wiggle the input shaft, it shows about .0015 movement.
Is it acceptable to wiggle this input shaft or is it supposed to be strictly push/pull movement?

 

[2001asp]

I had to go from a .038 to a .042. I put all my weight up and down. The shaft still spins freely, but virtually no in and out movement. To me, I did set up the guage and measured the in and out movement and found that you could get tons of different outcomes depending on how hard you yanked on the shaft. Promotion told me their secret and I went with that. .038 to the .042 and call it a day. Every car is different. The shaft I bought was a Tremec 26 spline.