Variable height row headers

I need rows that differ in height, so I'm using the following code:

<script>
function rowNumber(){return this.getRowProperty("index");}
obj.getRowTemplate().setClass("row", rowNumber);
</script>
<style>
.active-row-0 {height: 47px;}
.active-row-1 {height: 74px;}
</style>

This script/style combo sizes the row heights perfectly, but not the row headers. Is there a way to create variable-height row headers?