CSS float left not working right

DIV is a block element so you can give float or inline-block to your right div to take its actual width like this:

.right{float:right}

EDIT:

answer your comment below

if you give float to the divs then you have to clear its parent like this :

<div style="overflow:hidden"> 
    <div class="right" style="float: right;"><img src="images/members/bigava/crays.png" style="width: 630px; height: 130px;" /></div> 
    <div class="left" style="float: left;"><img src="images/members/ava/crays.jpg" style="width:120px; height:80px;" /></div> 
</div>