The capactitors in this kit are the exact same size as the originals. The forums at Macrumors.com have some pictures of these boards Here

Capacitor kit for Apple eMac
Capacitor kit for Apple eMac
Item# AppleEmac
$8.00

Product Description

This kit includes the following capacitors:

8X Nichicon HZ 6.3v 1800uF 10X16

6X Nichicon HZ 16v 1000uF 10X16