can someone give me advice on setting up a herbie overflow

[megs_clark]

Hi, Thanks for all the great advice, im just trying to track down a local drill bit (trying to get around waiting for the shipping) Seems easy to find 1 1/2 inch bits and 2" bits but can not find a 1 3/4 inch that i need for a one inch bulkhead. When i track one down i will be sure to use all your advice. Thanks for all the replys! Do you think i could drill with a 1 1/2 inch bit and use a diamond coated dremel to make it fit a 1" bulkhead? Or is that to risky