valve spring height question

http://www.summitracing.com/dom/parts/crn-99948-16
These are + 0.045

If you had single groove valves, you could use these.
http://www.summitracing.com/dom/parts/crn-99099-1

Also check your rocker to retainer clearance if you go to a higher retainer.

those retainers would be good but they are for dual and triple springs.