What lifter type do you have?
If it's Hydraulic, there is no lash adjustment, and if it's a solid non-roller type, I think its .018" intake and .020" exh lash standard, but your camshaft manufacture should call out the specs. I'm not familiar with the lash settings on a roller type solid lifter... Might be the same?
Use a feeler guage to check for coil bind at max lift when done setting lash. If you dont have spring left then you'll have to change them out or the cam... Once again, the camshaft manufacture would probably be able to give you an installed height for your springs and the open and closed spring pressure needed.