Ok. Not sure if it was a typo or I don't quite get it lol. You said a race car would be 1.88-1.90 and the same for a street car. Should I make them all 1.9 or intakes 1.88 and exhaust 1.9?
You missed the details....... For your cam/rocker combo:
Street, Comp 928@ 1.88-1.90
Race, Comp 929@ 1.88-1.90
If you verify the spring rate of your current springs is like a Comp 928(354lbs/in), then I'd adjust the installed height to be between 1.88-1.90 for all springs.
At that rate, the spread from 1.88-1.90 should only be 7lbs.
The common shims are .015/.030/.060, so you should be able to target 1.890 +/- .010.