My Signature pictures are too small, how do you make them bigger?

[93Corvette]

My signature pictures are tiny. So I went to:
Admin CP -> vBulletin Options -> User Groups -> UserGroup Manager -> Registered Users -> Edit/Go

I goto this block:



The orginal values were No, No, 500, 100, 10000

So to get the Signature pictures up, I changed it to Yes, Yes, 500, 100, 10000 which worked to get the picture posted. However, the picture is tiny (the same size as an Avatar). So, I ended up changing the values to Yes, Yes, 0, 0 , 0 thinking that this would override everything, just so I could prove I could get larger pictures there. But the small picture stills there.... So how do you make that picture bigger? It's the same size as an Avatar....