I have done 3 cc's in a bicep injection. But it really depends on how many mg's per cc. For example. 3 cc's of sustanon 250 would be 750 mg's - that would be to much IMO. But say you had 50 mg/cc of prop. that is just 150 mgs and you would be fine.
Also remember their is two heads to each Bi(long and short). Also you can inject in the brachialis muscle so with both arms that is six spots to inject so their is definatley room. I've done 3cc's of syntheorl and .75cc's of fina all into one belly with no problems.