I bought a set of stainless 1.6's just to have them on hand. they in no way compare to comp cams or crower. In fact the front rollers have .002/003 clearance on the pin. They would probably be o'k for a flat tappet spring with maybe 135/140 seat pressuse but after looking at these i wouldn't put on a set of PSI's valve springs with a 260lbs seat pressuse on them. I just wouldn't trust them that far.
Zip.