Recipe & dev times for Kodacolor-X 620 (exposed circa 1970) in Kodak HC-110 Dilution H (from concentrate) 1:63
20 minutes at 20°C/68.0°F
Agitate every 5 minutes.
Stop Bath - 1 minute
Ilford Rapid Fix 1:4 - 10 minutes
This film was exposed 40 years before being developed. I have no idea what storage conditions were like during that time. With that, results are very unlikely to duplicate.
Do not skip on fix time. In fact, I would add 5 more minutes to be safe. The c-22 emulsion is very thick.