Check end play with flywheel seal in? Options

[bbrock]

I think I already know the answer to this, but before I ruin an unused seal, I thought I'd get a ruling from the judges about whether you can get a good end play reading with the seal in place.

Thirty years ago I rebuilt the bottom end on my 2L engine and checked the end play with a feeler gauge. Then the project was put into deep sleep for decades before I finished the rebuild. Now I'm finally doing it and would like to recheck my work with a dial indicator just to be sure. So I set up my indicator on the flywheel and pulled the flywheel away from the case followed by a few very gentle taps on the impeller end of the crank shaft with a plastic mallet until it stopped moving. Zero the gauge and then squeeze the flywheel into the case with my hands. When I squeeze hard, the gauge reads about .0035" and when I let go, it moves back to about .002". I'm assuming the spring back is the seal pushing the crank back out a little. Would it be stupid to think I'm okay here?

I actually have a spare NOS seal I bought back when I started the rebuild. All I can find stamped on it is the size and FPM/ACM which I believe tells the inner and outer rubber material.

TIA