Stock 1.6 head  spring pressure? spring height?

btt

Valve spring free length:
                Standard, 50.46mm (1.9866in)
                Service limit 48.5mm (1.9094in).
Valve spring preload:
                 Standard, 24.8-29.2kg for 41.5mm (54.7-                  64.3lb/1.63in)
                 Service Limit, 22.8kg for 41.5mm  (50.2lb/1.63in)

Personally I wouldn't use anything outside of the limits for a new part. I have had bad experiences in the past with parts that were supposedly still servicable. It seems that you get a bit more wear each time the parts are disturbed because they need to break in a little bit again and that then takes them past the limit.

Thank you!