Bilge pump/sink drain and tank vent dimensions?
 

Looking to replace the original white thru hull drains with these and want to make sure they'll fit:
http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=013

Also looking at replacing the fuel and water tank vents with these:
http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=018

or these:
http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=023

I'm leaning towards the Attwood vents since they require a smaller mounting hole (in case I have to enlarge) and the vent head is removable for cleaning.