Norm, do you use regular saddle type jackstands with these? If so, do they show any kind of deflection?
Yes, I have two sets of jack stands, one set has the standard saddle similar to these. The other set my dad made 30+ years ago, they have a shallow saddle for supporting a rear end differential housing, just so you get a mental picture. The hockey pucks are the solution to needing a flat surface that will also conform to a saddle type jack stand. Believe me, they work great.