Violent Take-Off Shudder

I had the bottom end built in a machine shop and he did measure crank play. I do not have a recorded value, but he said that it was within spec. I trust my machinist quite a bit. Pretty stand up dude.
Replace the clutch before you tear up the crankshaft thrust bearing.
May be a good idea to measure it and the flywheel runout while you have it apart.
Good luck