It looks like you ordered some new valve springs, are you replacing all of them? If not, please be sure that you measure them to make sure they are in spec before re-using them.
I would also carefully measure any valves you plan to re-use, you've gone to a lot of trouble with buying a new head and all to have problems creep up sooner than you'd like due to out of spec parts. A full set of new OEM valves is about $300-$350 (in the U.S. at least).
I would hate to see you have a problem sooner than you'd like as happened with my head/valve job. I had a machine shop do the valve job and they didn't check the springs which were well under spec as I found out about 60K miles later. The weak springs caused the valves to not hold shut tightly, overheat and wear a groove in the sealing faces on all 24 of them (plus they were chineseium which I was not happy about at all), with thumbnail deep grooves and loss of compression in two cylinders. When measured, the springs were half of the rated spec.
I ended up redoing the valve job with all new OEM springs, all new OEM exhaust valve guides, and all new OEM valves and a much better machine shop. A bitter pill to swallow after an extensive rebuild which I did all the work on myself except the valve job.