OK I've answered my own question on this ...
What valve springs (and poundage) are you guys using for your Isky camshafts in your HS engines? (either with Isky's 230 or 220 camshaft @.050" checking)
I measured a Tecumseh 31672 valve spring at installed height of .865" and 5x coils @ .085" thick.
To avoid coil bind a minimum of .040" would be safe between coils.
Isky's .275" lift camshaft, definitely needs a spring with fewer coils to accommodate the lift.
Isky's .260" lift camshaft on .008" valve lash would leave .047" between coils.
However the quality of the Tecumseh springs looks dubious, I doubt they would hold their load rating for long, if not break.
Simple solution, order Isky springs for either Isky cam!