Having trouble getting my gauge to read accurate (digital gauge). Sent the gauge back to Cyberdine and they say everything checks out, so my next step is to swap out the sending unit in the tank. Haven't had a chance to drop the tank yet - want to do this all in one fail swoop hopefully Memorial Day weekend. but of course I have to order my parts ahead of time. eBay looks like the least expensive option for a new sending unit, but the auction I'm looking at specifically states that it's for a tank with a 2 1/2" opening. None of the other, more expensive units specify opening size, so I just wanted to hop on and see if it was safe to purchase. I know I could just drop the tank and check, but I won't have time until this weekend (no easy task for me and the space/tools I have - which is why I wanted to do it all at once). Here's the auction I'm looking at: http://cgi.ebay.com/ebaymotors/71-7...emQQcategoryZ46093QQihZ006QQitemZ160035943093 Thanks!!!