if you are hitting both heads, then 2 seperate cc's
if you are putting 2 cc's in one head (muscle) then just load the
needle with 2cc's and shoot, the oil will spread out if you rub your bi around after you shoot, which is something you should do anyway.
what type of oil are you using? and, let us know the difference in size, did you go up an inch, 3/4 etc..........
willK