What a question, it really has no possible answer.
How about this? You need shims, not buckets that are thinner to get to .005", take the .003, you would need one 2 thinner. Like 2 + 3 = 5, remember 2nd grade?
Buckets all the same, the shim snapped in the top is what changes.
Leave the .004" alone, close enough.
Past that the question is unanswerable since you have to know what shim is there to begin with before you can calculate what you need. That means pulling them to look for the number stamped on them or measuring to see what you've got.
DO NOT turn the engine with shims missing, you'll regret it instantly. Can bend valves super easy doing the work as well. Careful.
All this assumes a DOHC engine.