valve spring height question

The specs call for 1.850 installed height

maybe i should just use my stock springs. when i had my heads rebuilt last month the machine shop sais my stock springs were fine. But i went ahead and got new comp # 911. because i got a new 68 RR cam.
Can i just run my stock springs with that cam? the rest of the engine is rebuilt to stock specs besides the pistons ( KB 400) thanks